Sample records for temporary anionic states

  1. Temporary anion states of selected amino acids

    NASA Astrophysics Data System (ADS)

    Aflatooni, K.; Hitt, B.; Gallup, G. A.; Burrow, P. D.

    2001-10-01

    Vertical attachment energies for the formation of low-lying temporary anion states of glycine, alanine, phenylalanine, tryptophan, and proline in the gas phase are reported using electron transmission spectroscopy. Electron attachment into the empty π* orbital of the -COOH group was observed in all the compounds. Temporary anion states associated with the side groups in phenylalanine and tryptophan are found to be stabilized with respect to those in the reference compounds toluene and indole, respectively, by approximately 0.2 eV. We attribute this to electrostatic effects and explore, using simple theoretical models, the extent to which such anion states could be further stabilized if these amino acids were in zwitterionic form.

  2. Electron accommodation dynamics in the DNA base thymine

    NASA Astrophysics Data System (ADS)

    King, Sarah B.; Stephansen, Anne B.; Yokoi, Yuki; Yandell, Margaret A.; Kunin, Alice; Takayanagi, Toshiyuki; Neumark, Daniel M.

    2015-07-01

    The dynamics of electron attachment to the DNA base thymine are investigated using femtosecond time-resolved photoelectron imaging of the gas phase iodide-thymine (I-T) complex. An ultraviolet pump pulse ejects an electron from the iodide and prepares an iodine-thymine temporary negative ion that is photodetached with a near-IR probe pulse. The resulting photoelectrons are analyzed with velocity-map imaging. At excitation energies ranging from -120 meV to +90 meV with respect to the vertical detachment energy (VDE) of 4.05 eV for I-T, both the dipole-bound and valence-bound negative ions of thymine are observed. A slightly longer rise time for the valence-bound state than the dipole-bound state suggests that some of the dipole-bound anions convert to valence-bound species. No evidence is seen for a dipole-bound anion of thymine at higher excitation energies, in the range of 0.6 eV above the I-T VDE, which suggests that if the dipole-bound anion acts as a "doorway" to the valence-bound anion, it only does so at excitation energies near the VDE of the complex.

  3. Electron accommodation dynamics in the DNA base thymine.

    PubMed

    King, Sarah B; Stephansen, Anne B; Yokoi, Yuki; Yandell, Margaret A; Kunin, Alice; Takayanagi, Toshiyuki; Neumark, Daniel M

    2015-07-14

    The dynamics of electron attachment to the DNA base thymine are investigated using femtosecond time-resolved photoelectron imaging of the gas phase iodide-thymine (I(-)T) complex. An ultraviolet pump pulse ejects an electron from the iodide and prepares an iodine-thymine temporary negative ion that is photodetached with a near-IR probe pulse. The resulting photoelectrons are analyzed with velocity-map imaging. At excitation energies ranging from -120 meV to +90 meV with respect to the vertical detachment energy (VDE) of 4.05 eV for I(-)T, both the dipole-bound and valence-bound negative ions of thymine are observed. A slightly longer rise time for the valence-bound state than the dipole-bound state suggests that some of the dipole-bound anions convert to valence-bound species. No evidence is seen for a dipole-bound anion of thymine at higher excitation energies, in the range of 0.6 eV above the I(-)T VDE, which suggests that if the dipole-bound anion acts as a "doorway" to the valence-bound anion, it only does so at excitation energies near the VDE of the complex.

  4. Non-iterative triple excitations in equation-of-motion coupled-cluster theory for electron attachment with applications to bound and temporary anions.

    PubMed

    Jagau, Thomas-C

    2018-01-14

    The impact of residual electron correlation beyond the equation-of-motion coupled-cluster singles and doubles (EOM-CCSD) approximation on positions and widths of electronic resonances is investigated. To establish a method that accomplishes this task in an economical manner, several approaches proposed for the approximate treatment of triple excitations are reviewed with respect to their performance in the electron attachment (EA) variant of EOM-CC theory. The recently introduced EOM-CCSD(T)(a)* method [D. A. Matthews and J. F. Stanton, J. Chem. Phys. 145, 124102 (2016)], which includes non-iterative corrections to the reference and the target states, reliably reproduces vertical attachment energies from EOM-EA-CC calculations with single, double, and full triple excitations in contrast to schemes in which non-iterative corrections are applied only to the target states. Applications of EOM-EA-CCSD(T)(a)* augmented by a complex absorbing potential (CAP) to several temporary anions illustrate that shape resonances are well described by EOM-EA-CCSD, but that residual electron correlation often makes a non-negligible impact on their positions and widths. The positions of Feshbach resonances, on the other hand, are significantly improved when going from CAP-EOM-EA-CCSD to CAP-EOM-EA-CCSD(T)(a)*, but the correct energetic order of the relevant electronic states is still not achieved.

  5. Non-iterative triple excitations in equation-of-motion coupled-cluster theory for electron attachment with applications to bound and temporary anions

    NASA Astrophysics Data System (ADS)

    Jagau, Thomas-C.

    2018-01-01

    The impact of residual electron correlation beyond the equation-of-motion coupled-cluster singles and doubles (EOM-CCSD) approximation on positions and widths of electronic resonances is investigated. To establish a method that accomplishes this task in an economical manner, several approaches proposed for the approximate treatment of triple excitations are reviewed with respect to their performance in the electron attachment (EA) variant of EOM-CC theory. The recently introduced EOM-CCSD(T)(a)* method [D. A. Matthews and J. F. Stanton, J. Chem. Phys. 145, 124102 (2016)], which includes non-iterative corrections to the reference and the target states, reliably reproduces vertical attachment energies from EOM-EA-CC calculations with single, double, and full triple excitations in contrast to schemes in which non-iterative corrections are applied only to the target states. Applications of EOM-EA-CCSD(T)(a)* augmented by a complex absorbing potential (CAP) to several temporary anions illustrate that shape resonances are well described by EOM-EA-CCSD, but that residual electron correlation often makes a non-negligible impact on their positions and widths. The positions of Feshbach resonances, on the other hand, are significantly improved when going from CAP-EOM-EA-CCSD to CAP-EOM-EA-CCSD(T)(a)*, but the correct energetic order of the relevant electronic states is still not achieved.

  6. Short-range stabilizing potential for computing energies and lifetimes of temporary anions with extrapolation methods.

    PubMed

    Sommerfeld, Thomas; Ehara, Masahiro

    2015-01-21

    The energy of a temporary anion can be computed by adding a stabilizing potential to the molecular Hamiltonian, increasing the stabilization until the temporary state is turned into a bound state, and then further increasing the stabilization until enough bound state energies have been collected so that these can be extrapolated back to vanishing stabilization. The lifetime can be obtained from the same data, but only if the extrapolation is done through analytic continuation of the momentum as a function of the square root of a shifted stabilizing parameter. This method is known as analytic continuation of the coupling constant, and it requires--at least in principle--that the bound-state input data are computed with a short-range stabilizing potential. In the context of molecules and ab initio packages, long-range Coulomb stabilizing potentials are, however, far more convenient and have been used in the past with some success, although the error introduced by the long-rang nature of the stabilizing potential remains unknown. Here, we introduce a soft-Voronoi box potential that can serve as a short-range stabilizing potential. The difference between a Coulomb and the new stabilization is analyzed in detail for a one-dimensional model system as well as for the (2)Πu resonance of CO2(-), and in both cases, the extrapolation results are compared to independently computed resonance parameters, from complex scaling for the model, and from complex absorbing potential calculations for CO2(-). It is important to emphasize that for both the model and for CO2(-), all three sets of results have, respectively, been obtained with the same electronic structure method and basis set so that the theoretical description of the continuum can be directly compared. The new soft-Voronoi-box-based extrapolation is then used to study the influence of the size of diffuse and the valence basis sets on the computed resonance parameters.

  7. Time-resolved radiation chemistry: Dynamics of electron attachment to uracil following UV excitation of iodide-uracil complexes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    King, Sarah B.; Yandell, Margaret A.; Stephansen, Anne B.

    Electron attachment to uracil was investigated by applying time-resolved photoelectron imaging to iodide-uracil (I{sup –}U) complexes. In these studies, an ultraviolet pump pulse initiated charge transfer from the iodide to the uracil, and the resulting dynamics of the uracil temporary negative ion were probed. Five different excitation energies were used, 4.00 eV, 4.07 eV, 4.14 eV, 4.21 eV, and 4.66 eV. At the four lowest excitation energies, which lie near the vertical detachment energy of the I{sup –}U complex (4.11 eV), signatures of both the dipole bound (DB) as well as the valence bound (VB) anion of uracil were observed.more » In contrast, only the VB anion was observed at 4.66 eV, in agreement with previous experiments in this higher energy range. The early-time dynamics of both states were highly excitation energy dependent. The rise time of the DB anion signal was ∼250 fs at 4.00 eV and 4.07 eV, ∼120 fs at 4.14 eV and cross-correlation limited at 4.21 eV. The VB anion rise time also changed with excitation energy, ranging from 200 to 300 fs for excitation energies 4.00–4.21 eV, to a cross-correlation limited time at 4.66 eV. The results suggest that the DB state acts as a “doorway” state to the VB anion at 4.00–4.21 eV, while direct attachment to the VB anion occurs at 4.66 eV.« less

  8. Note: Coherent resonances observed in the dissociative electron attachment to carbon monoxide

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wang, Xu-Dong; Xuan, Chuan-Jin; Tian, Shan Xi, E-mail: sxtian@ustc.edu.cn

    Succeeding our previous finding about coherent interference of the resonant states of CO{sup −} formed by the low-energy electron attachment [Tian et al. Phys. Rev. A 88, 012708 (2013)], here we provide further evidence of the coherent interference. The completely backward distributions of the O{sup −} fragment of the temporary CO{sup −} are observed with anion velocity map imaging technique in an electron energy range of 11.3–12.6 eV and explained as the results of the coherent interferences of three resonant states. Furthermore, the state configuration of the interference is changed with the increase of electron attachment energy.

  9. In search for an optimal methodology to calculate the valence electron affinities of temporary anions.

    PubMed

    Puiatti, Marcelo; Vera, D Mariano A; Pierini, Adriana B

    2009-10-28

    Recently, we have proposed an approach for finding the valence anion ground state, based on the stabilization exerted by a polar solvent; the methodology used standard DFT methods and relatively inexpensive basis sets and yielded correct electron affinity (EA) values by gradually decreasing the dielectric constant of the medium. In order to address the overall performance of the new methodology, to find the best conditions for stabilizing the valence state and to evaluate its scope and limitations, we gathered a pool of 60 molecules, 25 of them bearing the conventional valence state as the ground anion and 35 for which the lowest anion state found holds the extra electron in a diffuse orbital around the molecule (non valence state). The results obtained by testing this representative set suggest a very good performance for most species having an experimental EA less negative than -3.0 eV; the correlation at the B3LYP/6-311+G(2df,p) level being y = 1.01x + 0.06, with a correlation index of 0.985. As an alternative, the time dependent DFT (TD-DFT) approach was also tested with both B3LYP and PBE0 functionals. The methodology we proposed shows a comparable or better accuracy with respect to TD-DFT, although the TD-DFT approach with the PBE0 functional is suggested as a suitable estimate for species with the most negative EAs (ca.-2.5 to -3.5 eV), for which stabilization strategies can hardly reach the valence state. As an application, a pool of 8 compounds of key biological interest with EAs which remain unknown or unclear were predicted using the new methodology.

  10. Resonance electron attachment to plant hormones and its likely connection with biochemical processes

    NASA Astrophysics Data System (ADS)

    Pshenichnyuk, Stanislav A.; Modelli, Alberto

    2014-01-01

    Gas-phase formation of temporary negative ion states via resonance attachment of low-energy (0-6 eV) electrons into vacant molecular orbitals of salicylic acid (I) and its derivatives 3-hydroxy- (II) and 4-hydroxybenzoic acid (III), 5-cloro salicylic acid (IV) and methyl salicylate (V) was investigated for the first time by electron transmission spectroscopy. The description of their empty-level structures was supported by density functional theory and Hartree-Fock calculations, using empirically calibrated linear equations to scale the calculated virtual orbital energies. Dissociative electron attachment spectroscopy (DEAS) was used to measure the fragment anion yields generated through dissociative decay channels of the parent molecular anions of compounds I-V, detected with a mass filter as a function of the incident electron energy in the 0-14 eV energy range. The most intense negative fragment produced by DEA to isomers I-III is the dehydrogenated molecular anion [M-H]-, mainly formed at incident electron energies around 1 eV. The vertical and adiabatic electron affinities were evaluated at the B3LYP/6-31+G(d) level as the anion/neutral total energy difference. The same theoretical method was also used for evaluation of the thermodynamic energy thresholds for production of the negative fragments observed in the DEA spectra. The gas-phase DEAS data can provide support for biochemical reaction mechanisms in vivo.

  11. Electron attachment to indole and related molecules

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Modelli, Alberto, E-mail: alberto.modelli@unibo.it; Centro Interdipartimentale di Ricerca in Scienze Ambientali; Jones, Derek, E-mail: d.jones@isof.cnr.it

    Gas-phase formation of temporary negative ion states via resonance attachment of low-energy (0–6 eV) electrons into vacant molecular orbitals of indoline (I), indene (II), indole (III), 2-methylen-1,3,3-trimethylindoline (IV), and 2,3,3-trimethyl-indolenine (V) was investigated for the first time by electron transmission spectroscopy (ETS). The description of their empty-level structures was supported by density functional theory and Hartree-Fock calculations, using empirically calibrated linear equations to scale the calculated virtual orbital energies. Dissociative electron attachment spectroscopy (DEAS) was used to measure the fragment anion yields generated through dissociative decay channels of the parent molecular anions of compounds I-V, detected with a mass filtermore » as a function of the incident electron energy in the 0–14 eV energy range. The vertical and adiabatic electron affinities were evaluated at the B3LYP/6-31+G(d) level as the anion/neutral total energy difference. The same theoretical method is also used for evaluation of the thermodynamic energy thresholds for production of the negative fragments observed in the DEA spectra. The loss of a hydrogen atom from the parent molecular anion ([M-H]{sup −}) provides the most intense signal in compounds I-IV. The gas-phase DEAS data can provide support for biochemical reaction mechanisms in vivo involving initial hydrogen abstraction from the nitrogen atom of the indole moiety, present in a variety of biologically important molecules.« less

  12. Complex basis functions for molecular resonances: Methodology and applications

    NASA Astrophysics Data System (ADS)

    White, Alec; McCurdy, C. William; Head-Gordon, Martin

    The computation of positions and widths of metastable electronic states is a challenge for molecular electronic structure theory because, in addition to the difficulty of the many-body problem, such states obey scattering boundary conditions. These resonances cannot be addressed with naïve application of traditional bound state electronic structure theory. Non-Hermitian electronic structure methods employing complex basis functions is one way that we may rigorously treat resonances within the framework of traditional electronic structure theory. In this talk, I will discuss our recent work in this area including the methodological extension from single determinant SCF-based approaches to highly correlated levels of wavefunction-based theory such as equation of motion coupled cluster and many-body perturbation theory. These approaches provide a hierarchy of theoretical methods for the computation of positions and widths of molecular resonances. Within this framework, we may also examine properties of resonances including the dependence of these parameters on molecular geometry. Some applications of these methods to temporary anions and dianions will also be discussed.

  13. 42 CFR 438.706 - Special rules for temporary management.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... temporary management. (a) Optional imposition of sanction. The State may impose temporary management only if... sanction. The State must impose temporary management (regardless of any other sanction that may be imposed... right to terminate enrollment. (c) Hearing. The State may not delay imposition of temporary management...

  14. Resonance electron attachment to plant hormones and its likely connection with biochemical processes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Pshenichnyuk, Stanislav A., E-mail: sapsh@anrb.ru; Modelli, Alberto

    Gas-phase formation of temporary negative ion states via resonance attachment of low-energy (0–6 eV) electrons into vacant molecular orbitals of salicylic acid (I) and its derivatives 3-hydroxy- (II) and 4-hydroxybenzoic acid (III), 5-cloro salicylic acid (IV) and methyl salicylate (V) was investigated for the first time by electron transmission spectroscopy. The description of their empty-level structures was supported by density functional theory and Hartree-Fock calculations, using empirically calibrated linear equations to scale the calculated virtual orbital energies. Dissociative electron attachment spectroscopy (DEAS) was used to measure the fragment anion yields generated through dissociative decay channels of the parent molecular anionsmore » of compounds I–V, detected with a mass filter as a function of the incident electron energy in the 0–14 eV energy range. The most intense negative fragment produced by DEA to isomers I–III is the dehydrogenated molecular anion [M–H]{sup −}, mainly formed at incident electron energies around 1 eV. The vertical and adiabatic electron affinities were evaluated at the B3LYP/6-31+G(d) level as the anion/neutral total energy difference. The same theoretical method was also used for evaluation of the thermodynamic energy thresholds for production of the negative fragments observed in the DEA spectra. The gas-phase DEAS data can provide support for biochemical reaction mechanisms in vivo.« less

  15. 22 CFR 9b.5 - Temporary Department of State press building passes.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Temporary Department of State press building passes. 9b.5 Section 9b.5 Foreign Relations DEPARTMENT OF STATE GENERAL REGULATIONS GOVERNING DEPARTMENT OF STATE PRESS BUILDING PASSES § 9b.5 Temporary Department of State press building passes. A media...

  16. 20 CFR 655.172 - Withdrawal of job order and application for temporary employment certification.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... temporary employment certification. 655.172 Section 655.172 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR TEMPORARY EMPLOYMENT OF FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process for Temporary Agricultural Employment in the United States (H-2A Workers) Post...

  17. 22 CFR 120.18 - Temporary import.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Temporary import. 120.18 Section 120.18 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS PURPOSE AND DEFINITIONS § 120.18 Temporary import. Temporary import means bringing into the United States from a foreign country any defense...

  18. 22 CFR 120.18 - Temporary import.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Temporary import. 120.18 Section 120.18 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS PURPOSE AND DEFINITIONS § 120.18 Temporary import. Temporary import means bringing into the United States from a foreign country any defense...

  19. 22 CFR 120.18 - Temporary import.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Temporary import. 120.18 Section 120.18 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS PURPOSE AND DEFINITIONS § 120.18 Temporary import. Temporary import means bringing into the United States from a foreign country any defense...

  20. 22 CFR 120.18 - Temporary import.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Temporary import. 120.18 Section 120.18 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS PURPOSE AND DEFINITIONS § 120.18 Temporary import. Temporary import means bringing into the United States from a foreign country any defense...

  1. 22 CFR 120.18 - Temporary import.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Temporary import. 120.18 Section 120.18 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS PURPOSE AND DEFINITIONS § 120.18 Temporary import. Temporary import means bringing into the United States from a foreign country any defense...

  2. 20 CFR 655.20 - Applications for temporary employment certification.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... LABOR TEMPORARY EMPLOYMENT OF FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process and... Nursing in the United States (H-2B Workers) § 655.20 Applications for temporary employment certification...

  3. 77 FR 12723 - Labor Certification Process for the Temporary Employment of Aliens in Agriculture in the United...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-02

    ... the Temporary Employment of Aliens in Agriculture in the United States; Announcement of Non- Material... reasons in great detail in the preamble of the ``Temporary Agricultural Employment of H-2A Aliens in the... set the AEWR. See ``Temporary Agricultural Employment of H-2A Aliens in the United States; Modernizing...

  4. Complete-active-space second-order perturbation theory (CASPT2//CASSCF) study of the dissociative electron attachment in canonical DNA nucleobases caused by low-energy electrons (0-3 eV)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Francés-Monerris, Antonio; Segarra-Martí, Javier; Merchán, Manuela

    Low-energy (0-3 eV) ballistic electrons originated during the irradiation of biological material can interact with DNA/RNA nucleobases yielding transient-anion species which undergo decompositions. Since the discovery that these reactions can eventually lead to strand breaking of the DNA chains, great efforts have been dedicated to their study. The main fragmentation at the 0-3 eV energy range is the ejection of a hydrogen atom from the specific nitrogen positions. In the present study, the methodological approach introduced in a previous work on uracil [I. González-Ramírez et al., J. Chem. Theory Comput. 8, 2769-2776 (2012)] is employed to study the DNA canonicalmore » nucleobases fragmentations of N–H bonds induced by low-energy electrons. The approach is based on minimum energy path and linear interpolation of internal coordinates computations along the N–H dissociation channels carried out at the complete-active-space self-consistent field//complete-active-space second-order perturbation theory level. On the basis of the calculated theoretical quantities, new assignations for the adenine and cytosine anion yield curves are provided. In addition, the π{sub 1}{sup −} and π{sub 2}{sup −} states of the pyrimidine nucleobases are expected to produce the temporary anions at electron energies close to 1 and 2 eV, respectively. Finally, the present theoretical results do not allow to discard neither the dipole-bound nor the valence-bound mechanisms in the range of energies explored, suggesting that both possibilities may coexist in the experiments carried out with the isolated nucleobases.« less

  5. Complete-active-space second-order perturbation theory (CASPT2//CASSCF) study of the dissociative electron attachment in canonical DNA nucleobases caused by low-energy electrons (0-3 eV).

    PubMed

    Francés-Monerris, Antonio; Segarra-Martí, Javier; Merchán, Manuela; Roca-Sanjuán, Daniel

    2015-12-07

    Low-energy (0-3 eV) ballistic electrons originated during the irradiation of biological material can interact with DNA/RNA nucleobases yielding transient-anion species which undergo decompositions. Since the discovery that these reactions can eventually lead to strand breaking of the DNA chains, great efforts have been dedicated to their study. The main fragmentation at the 0-3 eV energy range is the ejection of a hydrogen atom from the specific nitrogen positions. In the present study, the methodological approach introduced in a previous work on uracil [I. González-Ramírez et al., J. Chem. Theory Comput. 8, 2769-2776 (2012)] is employed to study the DNA canonical nucleobases fragmentations of N-H bonds induced by low-energy electrons. The approach is based on minimum energy path and linear interpolation of internal coordinates computations along the N-H dissociation channels carried out at the complete-active-space self-consistent field//complete-active-space second-order perturbation theory level. On the basis of the calculated theoretical quantities, new assignations for the adenine and cytosine anion yield curves are provided. In addition, the π1 (-) and π2 (-) states of the pyrimidine nucleobases are expected to produce the temporary anions at electron energies close to 1 and 2 eV, respectively. Finally, the present theoretical results do not allow to discard neither the dipole-bound nor the valence-bound mechanisms in the range of energies explored, suggesting that both possibilities may coexist in the experiments carried out with the isolated nucleobases.

  6. Complete-active-space second-order perturbation theory (CASPT2//CASSCF) study of the dissociative electron attachment in canonical DNA nucleobases caused by low-energy electrons (0-3 eV)

    NASA Astrophysics Data System (ADS)

    Francés-Monerris, Antonio; Segarra-Martí, Javier; Merchán, Manuela; Roca-Sanjuán, Daniel

    2015-12-01

    Low-energy (0-3 eV) ballistic electrons originated during the irradiation of biological material can interact with DNA/RNA nucleobases yielding transient-anion species which undergo decompositions. Since the discovery that these reactions can eventually lead to strand breaking of the DNA chains, great efforts have been dedicated to their study. The main fragmentation at the 0-3 eV energy range is the ejection of a hydrogen atom from the specific nitrogen positions. In the present study, the methodological approach introduced in a previous work on uracil [I. González-Ramírez et al., J. Chem. Theory Comput. 8, 2769-2776 (2012)] is employed to study the DNA canonical nucleobases fragmentations of N-H bonds induced by low-energy electrons. The approach is based on minimum energy path and linear interpolation of internal coordinates computations along the N-H dissociation channels carried out at the complete-active-space self-consistent field//complete-active-space second-order perturbation theory level. On the basis of the calculated theoretical quantities, new assignations for the adenine and cytosine anion yield curves are provided. In addition, the π1- and π2- states of the pyrimidine nucleobases are expected to produce the temporary anions at electron energies close to 1 and 2 eV, respectively. Finally, the present theoretical results do not allow to discard neither the dipole-bound nor the valence-bound mechanisms in the range of energies explored, suggesting that both possibilities may coexist in the experiments carried out with the isolated nucleobases.

  7. Urban Land: Study of Surface Run-off Composition and Its Dynamics

    NASA Astrophysics Data System (ADS)

    Palagin, E. D.; Gridneva, M. A.; Bykova, P. G.

    2017-11-01

    The qualitative composition of urban land surface run-off is liable to significant variations. To study surface run-off dynamics, to examine its behaviour and to discover reasons of these variations, it is relevant to use the mathematical apparatus technique of time series analysis. A seasonal decomposition procedure was applied to a temporary series of monthly dynamics with the annual frequency of seasonal variations in connection with a multiplicative model. The results of the quantitative chemical analysis of surface wastewater of the 22nd Partsjezd outlet in Samara for the period of 2004-2016 were used as basic data. As a result of the analysis, a seasonal pattern of variations in the composition of surface run-off in Samara was identified. Seasonal indices upon 15 waste-water quality indicators were defined. BOD (full), suspended materials, mineralization, chlorides, sulphates, ammonium-ion, nitrite-anion, nitrate-anion, phosphates (phosphorus), iron general, copper, zinc, aluminium, petroleum products, synthetic surfactants (anion-active). Based on the seasonal decomposition of the time series data, the contribution of trends, seasonal and accidental components of the variability of the surface run-off indicators was estimated.

  8. 77 FR 28764 - Temporary Non-agricultural Employment of H-2B Aliens in the United States

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-16

    ... DEPARTMENT OF LABOR Employment and Training Administration 20 CFR Part 655 RIN 1205-AB58 Temporary Non-agricultural Employment of H-2B Aliens in the United States AGENCY: Employment and Training... Temporary Non-agricultural Employment of H-2B Aliens in the United States, published February 21, 2012 (the...

  9. On the formation of anions: frequency-, angle-, and time-resolved photoelectron imaging of the menadione radical anion† †Electronic supplementary information (ESI) available: A summary of the ground-state geometries and molecular orbitals from the ab initio calculations; fitted residuals from the FA-PI simulation; plots of all spectra included in the frequency-resolved two-dimensional figure; and example time-resolved PE spectra from the 3.10 + 1.55 eV pump-probe experiments. See DOI: 10.1039/c4sc03491k Click here for additional data file.

    PubMed Central

    Bull, James N.; West, Christopher W.

    2015-01-01

    Frequency-, angle-, and time-resolved photoelectron imaging of gas-phase menadione (vitamin K3) radical anions was used to show that quasi-bound resonances of the anion can act as efficient doorway states to produce metastable ground electronic state anions on a sub-picosecond timescale. Several anion resonances have been experimentally observed and identified with the assistance of ab initio calculations, and ground state anion recovery was observed across the first 3 eV above threshold. Time-resolved measurements revealed the mechanism of electronic ground state anion formation, which first involves a cascade of very fast internal conversion processes to a bound electronic state that, in turn, decays by slower internal conversion to the ground state. Autodetachment processes from populated resonances are inefficient compared with electronic relaxation through internal conversion. The mechanistic understanding gained provides insight into the formation of radical anions in biological and astrochemical systems. PMID:29560245

  10. Dynamics of dipole- and valence bound anions in iodide-adenine binary complexes: A time-resolved photoelectron imaging and quantum mechanical investigation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Stephansen, Anne B.; King, Sarah B.; Li, Wei-Li

    2015-09-14

    Dipole bound (DB) and valence bound (VB) anions of binary iodide-adenine complexes have been studied using one-color and time-resolved photoelectron imaging at excitation energies near the vertical detachment energy. The experiments are complemented by quantum chemical calculations. One-color spectra show evidence for two adenine tautomers, the canonical, biologically relevant A9 tautomer and the A3 tautomer. In the UV-pump/IR-probe time-resolved experiments, transient adenine anions can be formed by electron transfer from the iodide. These experiments show signals from both DB and VB states of adenine anions formed on femto- and picosecond time scales, respectively. Analysis of the spectra and comparison withmore » calculations suggest that while both the A9 and A3 tautomers contribute to the DB signal, only the DB state of the A3 tautomer undergoes a transition to the VB anion. The VB anion of A9 is higher in energy than both the DB anion and the neutral, and the VB anion is therefore not accessible through the DB state. Experimental evidence of the metastable A9 VB anion is instead observed as a shape resonance in the one-color photoelectron spectra, as a result of UV absorption by A9 and subsequent electron transfer from iodide into the empty π-orbital. In contrast, the iodide-A3 complex constitutes an excellent example of how DB states can act as doorway state for VB anion formation when the VB state is energetically available.« less

  11. 42 CFR 488.415 - Temporary management.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 5 2012-10-01 2012-10-01 false Temporary management. 488.415 Section 488.415... Compliance for Long-Term Care Facilities with Deficiencies § 488.415 Temporary management. (a) Definition. Temporary management means the temporary appointment by CMS or the State of a substitute facility manager or...

  12. 42 CFR 488.415 - Temporary management.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 5 2014-10-01 2014-10-01 false Temporary management. 488.415 Section 488.415... Compliance for Long-Term Care Facilities with Deficiencies § 488.415 Temporary management. (a) Definition. Temporary management means the temporary appointment by CMS or the State of a substitute facility manager or...

  13. 42 CFR 488.415 - Temporary management.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 5 2013-10-01 2013-10-01 false Temporary management. 488.415 Section 488.415... Compliance for Long-Term Care Facilities with Deficiencies § 488.415 Temporary management. (a) Definition. Temporary management means the temporary appointment by CMS or the State of a substitute facility manager or...

  14. 42 CFR 488.415 - Temporary management.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 5 2011-10-01 2011-10-01 false Temporary management. 488.415 Section 488.415... Compliance for Long-Term Care Facilities with Deficiencies § 488.415 Temporary management. (a) Definition. Temporary management means the temporary appointment by CMS or the State of a substitute facility manager or...

  15. 42 CFR 488.415 - Temporary management.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 5 2010-10-01 2010-10-01 false Temporary management. 488.415 Section 488.415... Compliance for Long-Term Care Facilities with Deficiencies § 488.415 Temporary management. (a) Definition. Temporary management means the temporary appointment by CMS or the State of a substitute facility manager or...

  16. 8 CFR 244.14 - Withdrawal of Temporary Protected Status.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 8 Aliens and Nationality 1 2012-01-01 2012-01-01 false Withdrawal of Temporary Protected Status... TEMPORARY PROTECTED STATUS FOR NATIONALS OF DESIGNATED STATES § 244.14 Withdrawal of Temporary Protected Status. (a) Authority of USCIS. USCIS may withdraw the status of an alien granted Temporary Protected...

  17. 8 CFR 244.14 - Withdrawal of Temporary Protected Status.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 8 Aliens and Nationality 1 2014-01-01 2014-01-01 false Withdrawal of Temporary Protected Status... TEMPORARY PROTECTED STATUS FOR NATIONALS OF DESIGNATED STATES § 244.14 Withdrawal of Temporary Protected Status. (a) Authority of USCIS. USCIS may withdraw the status of an alien granted Temporary Protected...

  18. 8 CFR 244.14 - Withdrawal of Temporary Protected Status.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 8 Aliens and Nationality 1 2013-01-01 2013-01-01 false Withdrawal of Temporary Protected Status... TEMPORARY PROTECTED STATUS FOR NATIONALS OF DESIGNATED STATES § 244.14 Withdrawal of Temporary Protected Status. (a) Authority of USCIS. USCIS may withdraw the status of an alien granted Temporary Protected...

  19. 20 CFR 655.1310 - Validity and scope of temporary labor certifications.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... OF LABOR TEMPORARY EMPLOYMENT OF FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process for Temporary Agricultural Employment in the United States (H-2A Workers) § 655.1310 Validity and scope of... workers, the area of intended employment, the specific occupation and duties, and the employer(s...

  20. Low oxidation state aluminum-containing cluster anions: Cp{sup ∗}Al{sub n}H{sup −}, n = 1–3

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zhang, Xinxing; Ganteför, Gerd; Bowen, Kit, E-mail: AKandalam@wcupa.edu, E-mail: kbowen@jhu.edu

    Three new, low oxidation state, aluminum-containing cluster anions, Cp*Al{sub n}H{sup −}, n = 1–3, were prepared via reactions between aluminum hydride cluster anions, Al{sub n}H{sub m}{sup −}, and Cp*H ligands. These were characterized by mass spectrometry, anion photoelectron spectroscopy, and density functional theory based calculations. Agreement between the experimentally and theoretically determined vertical detachment energies and adiabatic detachment energies validated the computed geometrical structures. Reactions between aluminum hydride cluster anions and ligands provide a new avenue for discovering low oxidation state, ligated aluminum clusters.

  1. 8 CFR 215.9 - Temporary Worker Visa Exit Program.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 8 Aliens and Nationality 1 2011-01-01 2011-01-01 false Temporary Worker Visa Exit Program. 215.9... ALIENS DEPARTING FROM THE UNITED STATES § 215.9 Temporary Worker Visa Exit Program. An alien admitted on certain temporary worker visas at a port of entry participating in the Temporary Worker Visa Exit Program...

  2. 8 CFR 215.9 - Temporary Worker Visa Exit Program.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Temporary Worker Visa Exit Program. 215.9... ALIENS DEPARTING FROM THE UNITED STATES § 215.9 Temporary Worker Visa Exit Program. An alien admitted on certain temporary worker visas at a port of entry participating in the Temporary Worker Visa Exit Program...

  3. 8 CFR 215.9 - Temporary Worker Visa Exit Program.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 8 Aliens and Nationality 1 2013-01-01 2013-01-01 false Temporary Worker Visa Exit Program. 215.9... ALIENS DEPARTING FROM THE UNITED STATES § 215.9 Temporary Worker Visa Exit Program. An alien admitted on certain temporary worker visas at a port of entry participating in the Temporary Worker Visa Exit Program...

  4. 8 CFR 215.9 - Temporary Worker Visa Exit Program.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 8 Aliens and Nationality 1 2012-01-01 2012-01-01 false Temporary Worker Visa Exit Program. 215.9... ALIENS DEPARTING FROM THE UNITED STATES § 215.9 Temporary Worker Visa Exit Program. An alien admitted on certain temporary worker visas at a port of entry participating in the Temporary Worker Visa Exit Program...

  5. 8 CFR 215.9 - Temporary Worker Visa Exit Program.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 8 Aliens and Nationality 1 2014-01-01 2014-01-01 false Temporary Worker Visa Exit Program. 215.9... ALIENS DEPARTING FROM THE UNITED STATES § 215.9 Temporary Worker Visa Exit Program. An alien admitted on certain temporary worker visas at a port of entry participating in the Temporary Worker Visa Exit Program...

  6. 77 FR 24225 - Information Collection Approval; Temporary Non-Agricultural Employment of H-2B Aliens in the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-23

    ... DEPARTMENT OF LABOR Employment and Training Administration Information Collection Approval; Temporary Non-Agricultural Employment of H-2B Aliens in the United States AGENCY: Employment and Training... the Temporary Non-Agricultural Employment of H-2B Aliens in the United States; Final Rule. See 77 FR...

  7. Absorption characteristics of anions (I-, Br-, and Te2-) into zeolite in molten LiCl-KCl eutectic salt

    NASA Astrophysics Data System (ADS)

    Uozumi, Koichi; Sugihara, Kei; Kinoshita, Kensuke; Koyama, Tadafumi; Tsukada, Takeshi; Terai, Takayuki; Suzuki, Akihiro

    2014-04-01

    The behaviors of anion fission product (FP) elements to be absorbed into zeolite in molten LiCl-KCl eutectic salt were studied using iodine, bromine, and tellurium. First, the type-A zeolite was selected as the most suitable type of zeolite among type-A, type-X, and type-Y zeolites through experiments in which zeolites were heated together with LiCl-KCl-KI salt. As the next step, experiments in which the type-A zeolite was immersed in molten LiCl-KCl salt containing various concentrations of iodine, bromine, or tellurium were performed. The degree of absorption of the anion FP elements was evaluated using the separation factor (SF) value versus chlorine. Although the SF values for iodine and tellurium were higher than 1.0, which meant that these elements were absorbed into the type-A zeolite more intensively than chlorine in the salt, the corresponding value for bromine was approximately 1.0. The effects of coexisting cation FPs were also examined using cesium, strontium, and neodymium, and it was revealed that the SF values for iodine were less than those in the case without cation addition. On the other hand, the SF values for tellurium were not affected by the coexistence of cesium and strontium. Finally, the feasibility of the present pyroprocess flowsheet was evaluated by calculating the inventory of each anion FP in an electrorefiner based on the obtained SF values instead of temporary values for the anion FPs absorption, which were set due to lack of experimental data.

  8. 19 CFR 210.52 - Motions for temporary relief.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ....52 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Temporary Relief § 210.52 Motions for temporary relief... issuance of temporary relief, the Commission will be guided by practice under Rule 65 of the Federal Rules...

  9. Aza-Bambusurils En Route to Anion Transporters.

    PubMed

    Singh, Mandeep; Solel, Ephrath; Keinan, Ehud; Reany, Ofer

    2016-06-20

    Previous calculations of anion binding with various bambusuril analogs predicted that the replacement of oxygen by nitrogen atoms to produce semiaza-bambus[6]urils would award these new cavitands with multiple anion binding properties. This study validates the hypothesis by efficient synthesis, crystallography, thermogravimetric analysis and calorimetry. These unique host molecules are easily accessible from the corresponding semithio-bambusurils in a one-pot reaction, which converts a single anion receptor into a potential anion channel. Solid-state structures exhibit simultaneous accommodation of three anions, linearly positioned within the cavity along the main symmetry axis. The ability to hold anions at a short distance of about 4 Å is reminiscent of natural chloride channels in E. coli, which exhibit similar distances between their adjacent anion binding sites. The calculated transition-state energy for double-anion movement through the channel suggests that although these host-guest complexes are thermodynamically stable they enjoy high kinetic flexibility to render them efficient anion channels. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Low-lying π∗ resonances associated with cyano groups: A CAP/SAC-CI study

    NASA Astrophysics Data System (ADS)

    Ehara, Masahiro; Kanazawa, Yuki; Sommerfeld, Thomas

    2017-01-01

    The complex absorbing potential (CAP)/symmetry-adapted cluster-configuration interaction (SAC-CI) method is applied to low-lying π∗ resonance states of molecules containing one or two cyano (CN) groups. Benchmark calculations are carried out comparing the non-variational and approximate variational approach of SAC-CI and studying the selection threshold of operators. Experimental resonance positions from electron transmission spectroscopy (ETS) are reproduced provided the anticipated deviations due to vibronic effects are taken into account. Moreover, the calculated positions and widths agree well with those obtained in previous electron scattering calculations for HCN, CH3CN and their isonitriles. Based on our results, we suggest a reassignment of the experimental ETS of fumaronitrile and malononitrile. Our present results demonstrate again that the CAP/SAC-CI method reliably predicts low-lying π∗ resonances, and regarding the total numbers of molecules and resonances investigated, it is fair to say that it is presently the most extensively used high-level method in the temporary anion field.

  11. 20 CFR 655.209 - Invalidation of temporary labor certifications.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Invalidation of temporary labor... LABOR TEMPORARY EMPLOYMENT OF FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process for Logging Employment and Non-H-2A Agricultural Employment § 655.209 Invalidation of temporary labor...

  12. Temporary Transfer of Firearms From the Home to Prevent Suicide: Legal Obstacles and Recommendations.

    PubMed

    McCourt, Alexander D; Vernick, Jon S; Betz, Marian E; Brandspigel, Sara; Runyan, Carol W

    2017-01-01

    The presence of firearms in the home increases the risk of suicide for residents. As a result, clinicians and professional organizations recommend counseling about temporary removal of firearms from the home of potentially suicidal individuals. In some states, however, firearm laws may affect the ability to easily transfer a gun temporarily to reduce suicide risk. In particular, universal background check (UBC) laws-which require a background check whenever a gun is transferred, even by non-gun dealers-may also apply to temporary transfers intended to reduce suicide risk. Clinicians have previously reported that confusion regarding state firearm laws and uncertainty over the legality of a temporary transfer have affected their ability to effectively counsel patients. We summarize the laws of all 50 states and specifically examine the relevant firearm laws of 3 representative states with UBCs and different approaches-Maryland, Colorado, and California. We identify both helpful and problematic aspects of state laws regarding temporary transfer of firearms. We provide recommendations for amending UBC laws to make it easier for clinicians and patients to temporarily transfer firearms.

  13. 22 CFR 123.5 - Temporary export licenses.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... AND TEMPORARY IMPORT OF DEFENSE ARTICLES § 123.5 Temporary export licenses. (a) The Directorate of Defense Trade Controls may issue a license for the temporary export of unclassified defense articles (DSP... Defense Trade Controls if the article is to remain outside the United States beyond the period for which...

  14. 22 CFR 41.31 - Temporary visitors for business or pleasure.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Temporary visitors for business or pleasure. 41.31 Section 41.31 Foreign Relations DEPARTMENT OF STATE VISAS VISAS: DOCUMENTATION OF NONIMMIGRANTS UNDER THE IMMIGRATION AND NATIONALITY ACT, AS AMENDED Temporary Visitors § 41.31 Temporary visitors for...

  15. 22 CFR 41.31 - Temporary visitors for business or pleasure.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Temporary visitors for business or pleasure. 41.31 Section 41.31 Foreign Relations DEPARTMENT OF STATE VISAS VISAS: DOCUMENTATION OF NONIMMIGRANTS UNDER THE IMMIGRATION AND NATIONALITY ACT, AS AMENDED Temporary Visitors § 41.31 Temporary visitors for...

  16. 22 CFR 41.31 - Temporary visitors for business or pleasure.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Temporary visitors for business or pleasure. 41.31 Section 41.31 Foreign Relations DEPARTMENT OF STATE VISAS VISAS: DOCUMENTATION OF NONIMMIGRANTS UNDER THE IMMIGRATION AND NATIONALITY ACT, AS AMENDED Temporary Visitors § 41.31 Temporary visitors for...

  17. 22 CFR 41.31 - Temporary visitors for business or pleasure.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Temporary visitors for business or pleasure. 41.31 Section 41.31 Foreign Relations DEPARTMENT OF STATE VISAS VISAS: DOCUMENTATION OF NONIMMIGRANTS UNDER THE IMMIGRATION AND NATIONALITY ACT, AS AMENDED Temporary Visitors § 41.31 Temporary visitors for...

  18. 22 CFR 41.31 - Temporary visitors for business or pleasure.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Temporary visitors for business or pleasure. 41.31 Section 41.31 Foreign Relations DEPARTMENT OF STATE VISAS VISAS: DOCUMENTATION OF NONIMMIGRANTS UNDER THE IMMIGRATION AND NATIONALITY ACT, AS AMENDED Temporary Visitors § 41.31 Temporary visitors for...

  19. 33 CFR 174.29 - Temporary certificate of number.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Temporary certificate of number. 174.29 Section 174.29 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY....29 Temporary certificate of number. A State may issue a temporary certificate of number that is...

  20. 33 CFR 174.29 - Temporary certificate of number.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Temporary certificate of number. 174.29 Section 174.29 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY....29 Temporary certificate of number. A State may issue a temporary certificate of number that is...

  1. 8 CFR 1244.14 - Withdrawal of Temporary Protected Status.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 8 Aliens and Nationality 1 2013-01-01 2013-01-01 false Withdrawal of Temporary Protected Status... JUSTICE IMMIGRATION REGULATIONS TEMPORARY PROTECTED STATUS FOR NATIONALS OF DESIGNATED STATES § 1244.14 Withdrawal of Temporary Protected Status. (a) Authority of director. The director may withdraw the status of...

  2. 8 CFR 1244.14 - Withdrawal of Temporary Protected Status.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 8 Aliens and Nationality 1 2012-01-01 2012-01-01 false Withdrawal of Temporary Protected Status... JUSTICE IMMIGRATION REGULATIONS TEMPORARY PROTECTED STATUS FOR NATIONALS OF DESIGNATED STATES § 1244.14 Withdrawal of Temporary Protected Status. (a) Authority of director. The director may withdraw the status of...

  3. 8 CFR 1244.14 - Withdrawal of Temporary Protected Status.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Withdrawal of Temporary Protected Status... JUSTICE IMMIGRATION REGULATIONS TEMPORARY PROTECTED STATUS FOR NATIONALS OF DESIGNATED STATES § 1244.14 Withdrawal of Temporary Protected Status. (a) Authority of director. The director may withdraw the status of...

  4. 8 CFR 1244.14 - Withdrawal of Temporary Protected Status.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 8 Aliens and Nationality 1 2014-01-01 2014-01-01 false Withdrawal of Temporary Protected Status... JUSTICE IMMIGRATION REGULATIONS TEMPORARY PROTECTED STATUS FOR NATIONALS OF DESIGNATED STATES § 1244.14 Withdrawal of Temporary Protected Status. (a) Authority of director. The director may withdraw the status of...

  5. 8 CFR 1244.14 - Withdrawal of Temporary Protected Status.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 8 Aliens and Nationality 1 2011-01-01 2011-01-01 false Withdrawal of Temporary Protected Status... JUSTICE IMMIGRATION REGULATIONS TEMPORARY PROTECTED STATUS FOR NATIONALS OF DESIGNATED STATES § 1244.14 Withdrawal of Temporary Protected Status. (a) Authority of director. The director may withdraw the status of...

  6. 20 CFR 655.6 - Temporary need.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... WORKERS IN THE UNITED STATES Labor Certification Process and Enforcement of Attestations for Temporary Employment in Occupations Other Than Agriculture or Registered Nursing in the United States (H-2B Workers...

  7. A New Great Game: US-China Competition in Guam and the CNMI

    DTIC Science & Technology

    2017-06-01

    H-2B (temporary non- agricultural workers) visas is capped annually at a pre- 9 Report of the Visa...and the Economic Outlook 13 “H-2B Temporary Non- Agricultural Workers,” US Citizenship and Immigration...Services, November 2016, https://www.uscis.gov/working-united-states/temporary- workers/h-2b-temporary-non- agricultural -workers. 14 “H-2B Temporary

  8. 20 CFR 655.34 - Validity of temporary labor certifications.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... TEMPORARY EMPLOYMENT OF FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process and Enforcement of Attestations for Temporary Employment in Occupations Other Than Agriculture or Registered Nursing in the United...

  9. Solid state cathode materials for secondary magnesium-ion batteries that are compatible with magnesium metal anodes in water-free electrolyte

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Crowe, Adam J.; Bartlett, Bart M., E-mail: bartmb@umich.edu

    2016-10-15

    With high elemental abundance, large volumetric capacity, and dendrite-free metal deposition, magnesium metal anodes offer promise in beyond-lithium-ion batteries. However, the increased charge density associated with the divalent magnesium-ion (Mg{sup 2+}), relative to lithium-ion (Li{sup +}) hinders the ion-insertion and extraction processes within many materials and structures known for lithium-ion cathodes. As a result, many recent investigations incorporate known amounts of water within the electrolyte to provide temporary solvation of the Mg{sup 2+}, improving diffusion kinetics. Unfortunately with the addition of water, compatibility with magnesium metal anodes disappears due to forming an ion-insulating passivating layer. In this short review, recentmore » advances in solid state cathode materials for rechargeable magnesium-ion batteries are highlighted, with a focus on cathode materials that do not require water contaminated electrolyte solutions for ion insertion and extraction processes. - Graphical abstract: In this short review, we present candidate materials for reversible Mg-battery cathodes that are compatible with magnesium metal in water-free electrolytes. The data suggest that soft, polarizable anions are required for reversible cycling.« less

  10. 8 CFR 244.14 - Withdrawal of Temporary Protected Status.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Withdrawal of Temporary Protected Status... TEMPORARY PROTECTED STATUS FOR NATIONALS OF DESIGNATED STATES § 244.14 Withdrawal of Temporary Protected... Protected Status under section 244 of the Act at any time upon the occurrence of any of the following: (1...

  11. 8 CFR 244.14 - Withdrawal of Temporary Protected Status.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 8 Aliens and Nationality 1 2011-01-01 2011-01-01 false Withdrawal of Temporary Protected Status... TEMPORARY PROTECTED STATUS FOR NATIONALS OF DESIGNATED STATES § 244.14 Withdrawal of Temporary Protected... Protected Status under section 244 of the Act at any time upon the occurrence of any of the following: (1...

  12. Low-lying electronic structure of EuH, EuOH, and EuO neutrals and anions determined by anion photoelectron spectroscopy and DFT calculations

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kafader, Jared O.; Ray, Manisha; Jarrold, Caroline Chick, E-mail: cjarrold@indiana.edu

    2015-07-21

    The anion photoelectron (PE) spectra of EuH{sup −} and the PE spectrum of overlapping EuOH{sup −} and EuO{sup −} anions are presented and analyzed with supporting results from density functional theory calculations on the various anions and neutrals. Results point to ionically bound, high-spin species. EuH and EuOH anions and neutrals exhibit analogous electronic structures: Transitions from {sup 8}Σ{sup −} anion ground states arising from the 4f{sup 7}σ{sub 6s}{sup 2} superconfiguration to the close-lying neutral {sup 9}Σ{sup −} and {sup 7}Σ{sup −} states arising from the 4f{sup 7}σ{sub 6s} superconfiguration are observed spaced by an energy interval similar to themore » free Eu{sup +} [4f{sup 7}6s] {sup 9}S - {sup 7}S splitting. The electron affinities (EAs) of EuH and EuOH are determined to be 0.771 ± 0.009 eV and 0.700 ± 0.011 eV, respectively. Analysis of spectroscopic features attributed to EuO{sup −} photodetachment is complicated by the likely presence of two energetically competitive electronic states of EuO{sup −} populating the ion beam. However, based on the calculated relative energies of the close-lying anion states arising from the 4f{sup 7}σ{sub 6s} and 4f{sup 6}σ{sub 6s}{sup 2} configurations and the relative energies of the one-electron accessible 4f{sup 7} and 4f{sup 6}σ{sub 6s} neutral states based on ligand-field theory [M. Dulick, E. Murad, and R. F. Barrow, J. Chem. Phys. 85, 385 (1986)], the remaining features are consistent with the 4f{sup 6}σ{sub 6s}{sup 2}  {sup 7}Σ{sup −} and 4f{sup 7}σ{sub 6s}{sup 7}Σ{sup −} anion states lying very close in energy (the former was calculated to be 0.15 eV lower in energy than the latter), though the true anion ground state and neutral EA could not be established unambiguously. Calculations on the various EuO anion and neutral states suggest 4f-orbital overlap with 2p orbitals in species with 4f{sup 6} occupancy.« less

  13. Benzonitrile: Electron affinity, excited states, and anion solvation

    NASA Astrophysics Data System (ADS)

    Dixon, Andrew R.; Khuseynov, Dmitry; Sanov, Andrei

    2015-10-01

    We report a negative-ion photoelectron imaging study of benzonitrile and several of its hydrated, oxygenated, and homo-molecularly solvated cluster anions. The photodetachment from the unsolvated benzonitrile anion to the X ˜ 1 A 1 state of the neutral peaks at 58 ± 5 meV. This value is assigned as the vertical detachment energy (VDE) of the valence anion and the upper bound of adiabatic electron affinity (EA) of benzonitrile. The EA of the lowest excited electronic state of benzonitrile, a ˜ 3 A 1 , is determined as 3.41 ± 0.01 eV, corresponding to a 3.35 eV lower bound for the singlet-triplet splitting. The next excited state, the open-shell singlet A ˜ 1 A 1 , is found about an electron-volt above the triplet, with a VDE of 4.45 ± 0.01 eV. These results are in good agreement with ab initio calculations for neutral benzonitrile and its valence anion but do not preclude the existence of a dipole-bound state of similar energy and geometry. The step-wise and cumulative solvation energies of benzonitrile anions by several types of species were determined, including homo-molecular solvation by benzonitrile, hydration by 1-3 waters, oxygenation by 1-3 oxygen molecules, and mixed solvation by various combinations of O2, H2O, and benzonitrile. The plausible structures of the dimer anion of benzonitrile were examined using density functional theory and compared to the experimental observations. It is predicted that the dimer anion favors a stacked geometry capitalizing on the π-π interactions between the two partially charged benzonitrile moieties.

  14. State Maternity/Parental Leave Laws. Facts on Working Women No. 90-1.

    ERIC Educational Resources Information Center

    Women's Bureau (DOL), Washington, DC.

    The status of state maternity/parental leave laws throughout the United States is depicted in eight figures and three tables. Information is reported by state for maternity/parental leave laws, months of available leave, maternity/family illness laws, days of leave for family illness, temporary disability insurance laws, temporary disability…

  15. Challenges in Valuing Temporary Health States for Economic Evaluation: A Review of Empirical Applications of the Chained Time Trade-Off Method.

    PubMed

    Stoniute, Julija; Mott, David John; Shen, Jing

    2018-05-01

    The time trade-off (TTO) technique is commonly used to elicit health state utilities. Nevertheless, when the health states being valued are temporary, the TTO approach may be unsuitable. A variant of TTO- chained TTO-has been suggested to be used when the health states are temporary, but little research has been done on how chained TTO should be conducted. To systematically review the use of chained TTO in valuing temporary health states. A systematic literature search was conducted using the following major databases: Ovid MEDLINE(R), Embase, EBM Reviews, and PsycINFO. Abstracts (full articles if necessary) were screened by two independent reviewers, with a third reviewer resolving any disagreements. The resulting number of articles for review was low (n = 9). All the reviewed studies used face-to-face interviews, most had small sample sizes (<100), and all studies valued a small number of health states (<7), with time horizons typically ranging from 4 weeks to 1 year. All studies discussed methodological issues of using chained TTO, and some compared the results with those generated using other preference elicitation methods. Chained TTO appears to be feasible, consistent, and responsive and allows the valuation of temporary health states that would improve the efficiency and accuracy of decision making in health and health care. Nevertheless, the evidence is limited due to the low number of relevant studies in the literature. Further research is needed to examine the performance and validity of chained TTO compared with conventional TTO in the valuation of temporary health states. Copyright © 2017 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

  16. Highly Dynamic Anion-Quadrupole Networks in Proteins.

    PubMed

    Kapoor, Karan; Duff, Michael R; Upadhyay, Amit; Bucci, Joel C; Saxton, Arnold M; Hinde, Robert J; Howell, Elizabeth E; Baudry, Jerome

    2016-11-01

    The dynamics of anion-quadrupole (or anion-π) interactions formed between negatively charged (Asp/Glu) and aromatic (Phe) side chains are for the first time computationally characterized in RmlC (Protein Data Bank entry 1EP0 ), a homodimeric epimerase. Empirical force field-based molecular dynamics simulations predict anion-quadrupole pairs and triplets (anion-anion-π and anion-π-π) are formed by the protein during the simulated trajectory, which suggests that the anion-quadrupole interactions may provide a significant contribution to the overall stability of the protein, with an average of -1.6 kcal/mol per pair. Some anion-π interactions are predicted to form during the trajectory, extending the number of anion-quadrupole interactions beyond those predicted from crystal structure analysis. At the same time, some anion-π pairs observed in the crystal structure exhibit marginal stability. Overall, most anion-π interactions alternate between an "on" state, with significantly stabilizing energies, and an "off" state, with marginal or null stabilizing energies. The way proteins possibly compensate for transient loss of anion-quadrupole interactions is characterized in the RmlC aspartate 84-phenylalanine 112 anion-quadrupole pair observed in the crystal structure. A double-mutant cycle analysis of the thermal stability suggests a possible loss of anion-π interactions compensated by variations of hydration of the residues and formation of compensating electrostatic interactions. These results suggest that near-planar anion-quadrupole pairs can exist, sometimes transiently, which may play a role in maintaining the structural stability and function of the protein, in an otherwise very dynamic interplay of a nonbonded interaction network as well as solvent effects.

  17. A novel approach to analysing the regimes of temporary streams in relation to their controls on the composition and structure of aquatic biota

    NASA Astrophysics Data System (ADS)

    Gallart, F.; Prat, N.; García-Roger, E. M.; Latron, J.; Rieradevall, M.; Llorens, P.; Barberá, G. G.; Brito, D.; De Girolamo, A. M.; Lo Porto, A.; Buffagni, A.; Erba, S.; Neves, R.; Nikolaidis, N. P.; Perrin, J. L.; Querner, E. P.; Quiñonero, J. M.; Tournoud, M. G.; Tzoraki, O.; Skoulikidis, N.; Gómez, R.; Sánchez-Montoya, M. M.; Froebrich, J.

    2012-09-01

    Temporary streams are those water courses that undergo the recurrent cessation of flow or the complete drying of their channel. The structure and composition of biological communities in temporary stream reaches are strongly dependent on the temporal changes of the aquatic habitats determined by the hydrological conditions. Therefore, the structural and functional characteristics of aquatic fauna to assess the ecological quality of a temporary stream reach cannot be used without taking into account the controls imposed by the hydrological regime. This paper develops methods for analysing temporary streams' aquatic regimes, based on the definition of six aquatic states that summarize the transient sets of mesohabitats occurring on a given reach at a particular moment, depending on the hydrological conditions: Hyperrheic, Eurheic, Oligorheic, Arheic, Hyporheic and Edaphic. When the hydrological conditions lead to a change in the aquatic state, the structure and composition of the aquatic community changes according to the new set of available habitats. We used the water discharge records from gauging stations or simulations with rainfall-runoff models to infer the temporal patterns of occurrence of these states in the Aquatic States Frequency Graph we developed. The visual analysis of this graph is complemented by the development of two metrics which describe the permanence of flow and the seasonal predictability of zero flow periods. Finally, a classification of temporary streams in four aquatic regimes in terms of their influence over the development of aquatic life is updated from the existing classifications, with stream aquatic regimes defined as Permanent, Temporary-pools, Temporary-dry and Episodic. While aquatic regimes describe the long-term overall variability of the hydrological conditions of the river section and have been used for many years by hydrologists and ecologists, aquatic states describe the availability of mesohabitats in given periods that determine the presence of different biotic assemblages. This novel concept links hydrological and ecological conditions in a unique way. All these methods were implemented with data from eight temporary streams around the Mediterranean within the MIRAGE project. Their application was a precondition to assessing the ecological quality of these streams.

  18. Effect of Detergent on Electrical Properties of Squid Axon Membrane

    PubMed Central

    Kishimoto, Uichiro; Adelman, William J.

    1964-01-01

    The effects of detergents on squid giant axon action and resting potentials as well as membrane conductances in the voltage clamp have been studied. Anionic detergents (sodium lauryl sulfate, 0.1 to 1.0 mM; dimethyl benzene sulfonate, 1 to 20 mM, pH 7.6) cause a temporary increase and a later decrease of action potential height and the value of the resting potential. Cationic detergent (cetyl trimethyl ammonium chloride, 6 x 10-5 M or more, pH 7.6) generally brings about immediate and irreversible decreases in the action and resting potentials. Non-ionic detergent (tween 80, 0.1 M, pH 7.6) causes a slight reversible reduction of action potential height without affecting the value of the resting potential. Both anionic and cationic detergents generally decrease the sodium and potassium conductances irreversibly. The effect of non-ionic detergent is to decrease the sodium conductance reversibly, leaving the potassium conductance almost unchanged. PMID:14158665

  19. 20 CFR 655.151 - Newspaper advertisements.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ....151 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR TEMPORARY EMPLOYMENT OF FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process for Temporary Agricultural Employment in the United States (H-2A Workers) Post-Acceptance Requirements § 655.151 Newspaper...

  20. 20 CFR 655.160 - Determinations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR TEMPORARY EMPLOYMENT OF FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process for Temporary Agricultural Employment in the United States (H-2A Workers) Labor Certification Determinations § 655.160 Determinations. Except...

  1. 20 CFR 655.160 - Determinations.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR TEMPORARY EMPLOYMENT OF FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process for Temporary Agricultural Employment in the United States (H-2A Workers) Labor Certification Determinations § 655.160 Determinations. Except...

  2. Ultrafast dynamics of low-energy electron attachment via a non-valence correlation-bound state

    NASA Astrophysics Data System (ADS)

    Rogers, Joshua P.; Anstöter, Cate S.; Verlet, Jan R. R.

    2018-03-01

    The primary electron-attachment process in electron-driven chemistry represents one of the most fundamental chemical transformations with wide-ranging importance in science and technology. However, the mechanistic detail of the seemingly simple reaction of an electron and a neutral molecule to form an anion remains poorly understood, particularly at very low electron energies. Here, time-resolved photoelectron imaging was used to probe the electron-attachment process to a non-polar molecule using time-resolved methods. An initially populated diffuse non-valence state of the anion that is bound by correlation forces evolves coherently in ∼30 fs into a valence state of the anion. The extreme efficiency with which the correlation-bound state serves as a doorway state for low-energy electron attachment explains a number of electron-driven processes, such as anion formation in the interstellar medium and electron attachment to fullerenes.

  3. 75 FR 7367 - Announcement of Public Briefings on the Changes to the Labor Certification Process for the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-19

    ... for the Temporary Agricultural Employment of H-2A Aliens in the United States AGENCIES: Employment and... temporary or seasonal agricultural employment. See, Temporary Agricultural Employment of H-2A Aliens in the...

  4. 47 CFR 101.209 - Operation of stations at temporary fixed locations for communication between the United States...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... locations for communication between the United States and Canada or Mexico. 101.209 Section 101.209... communication between the United States and Canada or Mexico. Stations authorized to operate at temporary fixed... Mexico, without prior specific notification to, and authorization from, the Commission. Notification of...

  5. 20 CFR 655.170 - Extensions.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR TEMPORARY EMPLOYMENT OF FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process for Temporary Agricultural Employment in the United States (H-2A Workers) Post Certification § 655.170 Extensions. An employer may apply for...

  6. 20 CFR 655.163 - Certification fee.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR TEMPORARY EMPLOYMENT OF FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process for Temporary Agricultural Employment in the United States (H-2A Workers) Labor Certification Determinations § 655.163 Certification fee. A...

  7. 20 CFR 655.170 - Extensions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR TEMPORARY EMPLOYMENT OF FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process for Temporary Agricultural Employment in the United States (H-2A Workers) Post Certification § 655.170 Extensions. An employer may apply for...

  8. Developing a novel approach to analyse the regimes of temporary streams and their controls on aquatic biota

    NASA Astrophysics Data System (ADS)

    Gallart, F.; Prat, N.; García-Roger, E. M.; Latron, J.; Rieradevall, M.; Llorens, P.; Barberá, G. G.; Brito, D.; de Girolamo, A. M.; Lo Porto, A.; Neves, R.; Nikolaidis, N. P.; Perrin, J. L.; Querner, E. P.; Quiñonero, J. M.; Tournoud, M. G.; Tzoraki, O.; Froebrich, J.

    2011-10-01

    Temporary streams are those water courses that undergo the recurrent cessation of flow or the complete drying of their channel. The biological communities in temporary stream reaches are strongly dependent on the temporal changes of the aquatic habitats determined by the hydrological conditions. The use of the aquatic fauna structural and functional characteristics to assess the ecological quality of a temporary stream reach can not therefore be made without taking into account the controls imposed by the hydrological regime. This paper develops some methods for analysing temporary streams' aquatic regimes, based on the definition of six aquatic states that summarize the sets of mesohabitats occurring on a given reach at a particular moment, depending on the hydrological conditions: flood, riffles, connected, pools, dry and arid. We used the water discharge records from gauging stations or simulations using rainfall-runoff models to infer the temporal patterns of occurrence of these states using the developed aquatic states frequency graph. The visual analysis of this graph is complemented by the development of two metrics based on the permanence of flow and the seasonal predictability of zero flow periods. Finally, a classification of the aquatic regimes of temporary streams in terms of their influence over the development of aquatic life is put forward, defining Permanent, Temporary-pools, Temporary-dry and Episodic regime types. All these methods were tested with data from eight temporary streams around the Mediterranean from MIRAGE project and its application was a precondition to assess the ecological quality of these streams using the current methods prescribed in the European Water Framework Directive for macroinvertebrate communities.

  9. 19 CFR 210.77 - Temporary emergency action.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 3 2010-04-01 2010-04-01 false Temporary emergency action. 210.77 Section 210.77 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Enforcement Procedures and Advisory Opinions § 210.77 Temporary...

  10. 20 CFR 655.161 - Criteria for certification.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 655.161 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR TEMPORARY EMPLOYMENT OF FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process for Temporary Agricultural Employment in the United States (H-2A Workers) Labor Certification Determinations § 655.161 Criteria for...

  11. 20 CFR 655.154 - Additional positive recruitment.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Section 655.154 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR TEMPORARY EMPLOYMENT OF FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process for Temporary Agricultural Employment in the United States (H-2A Workers) Post-Acceptance Requirements § 655.154 Additional positive...

  12. 20 CFR 655.167 - Document retention requirements.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Section 655.167 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR TEMPORARY EMPLOYMENT OF FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process for Temporary Agricultural Employment in the United States (H-2A Workers) Labor Certification Determinations § 655.167 Document...

  13. 20 CFR 655.102 - Special procedures.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR TEMPORARY EMPLOYMENT OF FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process for Temporary Agricultural Employment in the United States (H-2A Workers) § 655.102 Special procedures. To provide for a limited degree of...

  14. Photoelectron Spectroscopy Study of Quinonimides

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hossain, Ekram; Deng, Shihu M.; Gozem, Samer

    Structures and energetics of o-, m- and p-quinonimide anions (OC6H4N) and quinoniminyl radicals have been investigated by using negative ion photoelectron spectroscopy. Modeling of the photoelectron spectrum of the ortho isomer shows that the ground state of the anion is a triplet, while the quinoniminyl radical has a doublet ground state with a doublet-quartet splitting of 35.5 kcal/mol. The para radical has doublet ground state, but a band for a quartet state is missing from the photoelectron spectrum indicating that the anion has a singlet ground state, in contrast to previously reported calculations. The theoretical modeling is revisited here, andmore » it is shown that accurate predictions for the electronic structure of the para quinonimide anion require both an accurate account of electron correlation and a sufficiently diffuse basis set. Electron affinities of o- and p-quinoniminyl radicals are measured to be 1.715 ± 0.010 and 1.675 ± 0.010 eV, respectively. The photoelectron spectrum of the m-quinonimide anion shows that the ion undergoes several different rearrangements, including a rearrangement to the energetically favorable para isomer. Such rearrangements preclude a meaningful analysis of the experimental spectrum.« less

  15. 20 CFR 655.182 - Debarment.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... WORKERS IN THE UNITED STATES Labor Certification Process for Temporary Agricultural Employment in the United States (H-2A Workers) Integrity Measures § 655.182 Debarment. (a) Debarment of an employer. The... or condition of its temporary labor certification, with respect to H-2A workers, workers in...

  16. Proposed positive protection guidance for Kansas : synthesis of work zone positive protection devices and state of practice.

    DOT National Transportation Integrated Search

    2013-02-01

    The United States experiences over 700 fatalities and over 37,000 injuries each year in temporary : construction and maintenance work zones. The Federal Highway Administration (FHWA) has implemented : Temporary Traffic Control Devices 23 CFR 630 Subp...

  17. 20 CFR 655.120 - Offered wage rate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR TEMPORARY EMPLOYMENT OF FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process for Temporary Agricultural Employment in the United States (H-2A Workers) Prefiling Procedures § 655.120 Offered wage rate. (a) To comply with...

  18. 20 CFR 655.158 - Duration of positive recruitment.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Section 655.158 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR TEMPORARY EMPLOYMENT OF FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process for Temporary Agricultural Employment in the United States (H-2A Workers) Post-Acceptance Requirements § 655.158 Duration of positive...

  19. 19 CFR 210.66 - Initial determination concerning temporary relief; Commission action thereon.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 3 2010-04-01 2010-04-01 false Initial determination concerning temporary relief; Commission action thereon. 210.66 Section 210.66 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Temporary Relief § 210.66 Initial...

  20. 19 CFR 210.69 - Approval of complainant's temporary relief bond.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 3 2010-04-01 2010-04-01 false Approval of complainant's temporary relief bond. 210.69 Section 210.69 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Temporary Relief § 210.69 Approval of...

  1. 22 CFR 126.2 - Temporary suspension or modification of this subchapter.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Temporary suspension or modification of this subchapter. 126.2 Section 126.2 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS GENERAL POLICIES AND PROVISIONS § 126.2 Temporary suspension or modification of this subchapter...

  2. 22 CFR 126.2 - Temporary suspension or modification of this subchapter.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Temporary suspension or modification of this subchapter. 126.2 Section 126.2 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS GENERAL POLICIES AND PROVISIONS § 126.2 Temporary suspension or modification of this subchapter...

  3. 22 CFR 126.2 - Temporary suspension or modification of this subchapter.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Temporary suspension or modification of this subchapter. 126.2 Section 126.2 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS GENERAL POLICIES AND PROVISIONS § 126.2 Temporary suspension or modification of this subchapter...

  4. 22 CFR 126.2 - Temporary suspension or modification of this subchapter.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Temporary suspension or modification of this subchapter. 126.2 Section 126.2 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS GENERAL POLICIES AND PROVISIONS § 126.2 Temporary suspension or modification of this subchapter...

  5. Proposed positive protection guidance for Kansas : synthesis of work zone positive protection devices and state practice : [technical summary].

    DOT National Transportation Integrated Search

    2013-02-01

    The United States experiences over 700 fatalities and over 37,000 injuries each year in : temporary construction and maintenance work zones. The Federal Highway Administration : (FHWA) has implemented Temporary Traffic Control Devices 23 CFR 630 Subp...

  6. Decay dynamics of nascent acetonitrile and nitromethane dipole-bound anions produced by intracluster charge-transfer

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yandell, Margaret A.; King, Sarah B.; Neumark, Daniel M., E-mail: dneumark@berkeley.edu

    2014-05-14

    Decay dynamics of nascent dipole bound states of acetonitrile and nitromethane are examined using time-resolved photoelectron imaging of iodide-acetonitrile (I{sup −}·CH{sub 3}CN) and iodide-nitromethane (I{sup −}·CH{sub 3}NO{sub 2}) complexes. Dipole-bound anions are created by UV-initiated electron transfer to the molecule of interest from the associated iodide ion at energies just below the vertical detachment energy of the halide-molecule complex. The acetonitrile anion is observed to decay biexponentially with time constants in the range of 4–900 ps. In contrast, the dipole bound state of nitromethane decays rapidly over 400 fs to form the valence bound anion. The nitromethane valence anion speciesmore » then decays biexponentially with time constants of 2 ps and 1200 ps. The biexponential decay dynamics in acetonitrile are interpreted as iodine atom loss and autodetachment from the excited dipole-bound anion, followed by slower autodetachment of the relaxed metastable ion, while the dynamics of the nitromethane system suggest that a dipole-bound anion to valence anion transition proceeds via intramolecular vibrational energy redistribution to nitro group modes in the vicinity of the iodine atom.« less

  7. Decay dynamics of nascent acetonitrile and nitromethane dipole-bound anions produced by intracluster charge-transfer.

    PubMed

    Yandell, Margaret A; King, Sarah B; Neumark, Daniel M

    2014-05-14

    Decay dynamics of nascent dipole bound states of acetonitrile and nitromethane are examined using time-resolved photoelectron imaging of iodide-acetonitrile (I(-)·CH3CN) and iodide-nitromethane (I(-)·CH3NO2) complexes. Dipole-bound anions are created by UV-initiated electron transfer to the molecule of interest from the associated iodide ion at energies just below the vertical detachment energy of the halide-molecule complex. The acetonitrile anion is observed to decay biexponentially with time constants in the range of 4-900 ps. In contrast, the dipole bound state of nitromethane decays rapidly over 400 fs to form the valence bound anion. The nitromethane valence anion species then decays biexponentially with time constants of 2 ps and 1200 ps. The biexponential decay dynamics in acetonitrile are interpreted as iodine atom loss and autodetachment from the excited dipole-bound anion, followed by slower autodetachment of the relaxed metastable ion, while the dynamics of the nitromethane system suggest that a dipole-bound anion to valence anion transition proceeds via intramolecular vibrational energy redistribution to nitro group modes in the vicinity of the iodine atom.

  8. 20 CFR 655.166 - Requests for determinations based on nonavailability of U.S. workers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... nonavailability of U.S. workers. 655.166 Section 655.166 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR TEMPORARY EMPLOYMENT OF FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process for Temporary Agricultural Employment in the United States (H-2A Workers) Labor...

  9. 20 CFR 655.166 - Requests for determinations based on nonavailability of U.S. workers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... nonavailability of U.S. workers. 655.166 Section 655.166 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR TEMPORARY EMPLOYMENT OF FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process for Temporary Agricultural Employment in the United States (H-2A Workers) Labor...

  10. 20 CFR 655.101 - Authority of the Office of Foreign Labor Certification (OFLC) Administrator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Certification (OFLC) Administrator. 655.101 Section 655.101 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR TEMPORARY EMPLOYMENT OF FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process for Temporary Agricultural Employment in the United States (H-2A Workers) § 655.101...

  11. 20 CFR 655.100 - Scope and purpose of subpart B.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Section 655.100 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR TEMPORARY EMPLOYMENT OF FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process for Temporary Agricultural Employment in the United States (H-2A Workers) § 655.100 Scope and purpose of subpart B. This subpart sets...

  12. 20 CFR 655.100 - Scope and purpose of subpart B.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Section 655.100 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR TEMPORARY EMPLOYMENT OF FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process for Temporary Agricultural Employment in the United States (H-2A Workers) § 655.100 Scope and purpose of subpart B. This subpart sets...

  13. 20 CFR 655.151 - Newspaper advertisements.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Newspaper advertisements. 655.151 Section 655.151 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR TEMPORARY EMPLOYMENT OF FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process for Temporary Agricultural Employment in the United States (H-2A Workers)...

  14. 22 CFR 123.4 - Temporary import license exemptions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Temporary import license exemptions. 123.4 Section 123.4 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS LICENSES FOR..., demonstration or marketing in the United States and is subsequently returned to the country from which it was...

  15. Anions in Electrothermal Supercharging of Proteins with Electrospray Ionization Follow a Reverse Hofmeister Series

    PubMed Central

    2015-01-01

    The effects of different anions on the extent of electrothermal supercharging of proteins from aqueous ammonium and sodium salt solutions were investigated. Sulfate and hydrogen phosphate are the most effective anions at producing high charge state protein ions from buffered aqueous solution, whereas iodide and perchlorate are ineffective with electrothermal supercharging. The propensity for these anions to produce high charge state protein ions follows the following trend: sulfate > hydrogen phosphate > thiocyanate > bicarbonate > chloride > formate ≈ bromide > acetate > iodide > perchlorate. This trend correlates with the reverse Hofmeister series over a wide range of salt concentrations (1 mM to 2 M) and with several physical properties, including solvent surface tension, anion viscosity B-coefficient, and anion surface/bulk partitioning coefficient, all of which are related to the Hofmeister series. The effectiveness of electrothermal supercharging does not depend on bubble formation, either from thermal degradation of the buffer or from coalescence of dissolved gas. These results provide evidence that the effect of different ions in the formation of high charge state ions by electrothermal supercharging is largely a result of Hofmeister effects on protein stability leading to protein unfolding in the heated ESI droplet. PMID:24410546

  16. 22 CFR 123.1 - Requirement for export or temporary import licenses.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... licenses. 123.1 Section 123.1 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS LICENSES FOR THE EXPORT AND TEMPORARY IMPORT OF DEFENSE ARTICLES § 123.1 Requirement for export or temporary import licenses. (a) Any person who intends to export or to import temporarily a defense article...

  17. 15 CFR 740.9 - Temporary imports, exports, and reexports (TMP).

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... the end of the beta test period as defined by the software producer or, if the software producer does... States; and exports and reexports of beta test software. (a) Temporary exports and reexports—(1) Scope. You may export and reexport commodities and software for temporary use abroad (including use in...

  18. 15 CFR 740.9 - Temporary imports, exports, and reexports (TMP).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... the end of the beta test period as defined by the software producer or, if the software producer does... States; and exports and reexports of beta test software. (a) Temporary exports and reexports—(1) Scope. You may export and reexport commodities and software for temporary use abroad (including use in...

  19. Modeling Photoelectron Spectra of CuO, Cu2O, and CuO2 Anions with Equation-of-Motion Coupled-Cluster Methods: An Adventure in Fock Space.

    PubMed

    Orms, Natalie; Krylov, Anna I

    2018-04-12

    The experimental photoelectron spectra of di- and triatomic copper oxide anions have been reported previously. We present an analysis of the experimental spectra of the CuO - , Cu 2 O - , and CuO 2 - anions using equation-of-motion coupled-cluster (EOM-CC) methods. The open-shell electronic structure of each molecule demands a unique combination of EOM-CC methods to achieve an accurate and balanced representation of the multiconfigurational anionic- and neutral-state manifolds. Analysis of the Dyson orbitals associated with photodetachment from CuO - reveals the strong non-Koopmans character of the CuO states. For the lowest detachment energy, a good agreement between theoretical and experimental values is obtained with CCSD(T) (coupled-cluster with single and double excitations and perturbative account of triple excitations). The (T) correction is particularly important for Cu 2 O - . Use of a relativistic pseudopotential and matching basis set improves the quality of results in most cases. EOM-DIP-CCSD analysis of the low-lying states of CuO 2 - reveals multiple singlet and triplet anionic states near the triplet ground state, adding an extra layer of complexity to the interpretation of the experimental CuO 2 - photoelectron spectrum.

  20. 26 CFR 31.3121(b)(18)-1 - Services performed by a resident of the Republic of the Philippines while temporarily in Guam.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... coming temporarily to the United States to perform temporary services of an exceptional nature requiring merit and ability; or (ii) who is coming temporarily to the United States to perform other temporary... this country; or (iii) who is coming temporarily to the United States as an industrial trainee; [T.D...

  1. 26 CFR 31.3121(b)(18)-1 - Services performed by a resident of the Republic of the Philippines while temporarily in Guam.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... coming temporarily to the United States to perform temporary services of an exceptional nature requiring merit and ability; or (ii) who is coming temporarily to the United States to perform other temporary... this country; or (iii) who is coming temporarily to the United States as an industrial trainee; [T.D...

  2. 26 CFR 31.3121(b)(18)-1 - Services performed by a resident of the Republic of the Philippines while temporarily in Guam.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... coming temporarily to the United States to perform temporary services of an exceptional nature requiring merit and ability; or (ii) who is coming temporarily to the United States to perform other temporary... this country; or (iii) who is coming temporarily to the United States as an industrial trainee; [T.D...

  3. 26 CFR 31.3121(b)(18)-1 - Services performed by a resident of the Republic of the Philippines while temporarily in Guam.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... coming temporarily to the United States to perform temporary services of an exceptional nature requiring merit and ability; or (ii) who is coming temporarily to the United States to perform other temporary... this country; or (iii) who is coming temporarily to the United States as an industrial trainee; [T.D...

  4. Excited State Trends in Bidirectionally Expanded Closed-Shell PAH and PANH Anions

    PubMed Central

    Moore, Megan M.; Lee, Timothy J.

    2018-01-01

    Some anions are known to exhibit excited states independent of external forces such as dipole moments and induced polarizabilities. Such states exist simply as a result of the stabilization of valence accepting orbitals whereby the binding energy of the extra electron is greater than the valence excitation energy. Closed-shell anions are interesting candidates for such transitions since their ground-state, spin-paired nature makes the anions more stable from the beginning. Consequently, this work shows the point beyond which deprotonated, closed-shell polycyclic aromatic hydrocarbons (PAHs) and those PAHs containing nitrogen heteroatoms (PANHs) will exhibit valence excited states. This behavior has already been demonstrated in some PANHs and for anistropically-extended PAHs. This work establishes a general trend for PAHs/PANHs of arbitrary size and directional extension, whether in one dimension or two. Once seven six-membered rings make up a PAH/PANH, valence excited states are present. For most classes of PAHs/PANHs, this number is closer to four. Even though most of these excited states are weak absorbers, the sheer number of PAHs present in various astronomical environments should make them significant contributors to astronomical spectra. PMID:27585793

  5. 20 CFR 655.1305 - Assurances and obligations of H-2A employers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ..., including employment-related health and safety laws; (2) Provide for or secure housing for those workers who... LABOR TEMPORARY EMPLOYMENT OF FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process for Temporary Agricultural Employment in the United States (H-2A Workers) § 655.1305 Assurances and obligations...

  6. 78 FR 1260 - Labor Certification Process for the Temporary Employment of Aliens in Agriculture in the United...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-08

    ... DEPARTMENT OF LABOR Employment and Training Administration Labor Certification Process for the Temporary Employment of Aliens in Agriculture in the United States: Prevailing Wage Rates for Certain... Agriculture (USDA) farm production region that includes another State either with its own wage rate finding or...

  7. 20 CFR 655.122 - Contents of job offers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false Contents of job offers. 655.122 Section 655.122 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR TEMPORARY EMPLOYMENT OF FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process for Temporary Agricultural Employment in the United States (H-2A Workers)...

  8. 20 CFR 655.1304 - Contents of job offers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false Contents of job offers. 655.1304 Section 655.1304 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR TEMPORARY EMPLOYMENT OF FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process for Temporary Agricultural Employment in the United States (H-2A Workers) §...

  9. 42 CFR 423.415 - Temporary waivers for entities seeking to offer a prescription drug plan in more than one State...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICARE PROGRAM VOLUNTARY MEDICARE PRESCRIPTION DRUG BENEFIT Organization Compliance with State Law and Preemption by Federal Law § 423.415 Temporary waivers for entities seeking to offer a prescription drug plan in more...

  10. 47 CFR 101.209 - Operation of stations at temporary fixed locations for communication between the United States...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false Operation of stations at temporary fixed locations for communication between the United States and Canada or Mexico. 101.209 Section 101.209 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE...

  11. 47 CFR 101.209 - Operation of stations at temporary fixed locations for communication between the United States...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Operation of stations at temporary fixed locations for communication between the United States and Canada or Mexico. 101.209 Section 101.209 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE...

  12. 47 CFR 101.209 - Operation of stations at temporary fixed locations for communication between the United States...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Operation of stations at temporary fixed locations for communication between the United States and Canada or Mexico. 101.209 Section 101.209 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE...

  13. 47 CFR 101.209 - Operation of stations at temporary fixed locations for communication between the United States...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false Operation of stations at temporary fixed locations for communication between the United States and Canada or Mexico. 101.209 Section 101.209 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE...

  14. 41 CFR 302-8.106 - May I change from temporary to extended storage?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... temporary to extended storage? 302-8.106 Section 302-8.106 Public Contracts and Property Management Federal... EXTENDED STORAGE OF HOUSEHOLD GOODS (HHG) Extended Storage During Assignment to Isolated Locations in the Continental United States (CONUS) § 302-8.106 May I change from temporary to extended storage? Yes, you may...

  15. 41 CFR 302-8.106 - May I change from temporary to extended storage?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... temporary to extended storage? 302-8.106 Section 302-8.106 Public Contracts and Property Management Federal... EXTENDED STORAGE OF HOUSEHOLD GOODS (HHG) Extended Storage During Assignment to Isolated Locations in the Continental United States (CONUS) § 302-8.106 May I change from temporary to extended storage? Yes, you may...

  16. 41 CFR 302-8.106 - May I change from temporary to extended storage?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... temporary to extended storage? 302-8.106 Section 302-8.106 Public Contracts and Property Management Federal... EXTENDED STORAGE OF HOUSEHOLD GOODS (HHG) Extended Storage During Assignment to Isolated Locations in the Continental United States (CONUS) § 302-8.106 May I change from temporary to extended storage? Yes, you may...

  17. Photophysics and Photochemistry of 2-Aminobenzoic Acid Anion in Aqueous Solution

    NASA Astrophysics Data System (ADS)

    Pozdnyakov, Ivan P.; Plyusnin, Victor F.; Grivin, Vjacheslav P.

    2009-11-01

    Nanosecond laser flash photolysis and absorption and fluorescence spectroscopy were used to study photochemical processes of 2-aminobenzoic acid anion (ABA-) in aqueous solutions. Excitation of this species gives rise to the ABA- triplet state to the ABA• radical and to the hydrated electron (eaq-). The last two species result from two-photon processes. In a neutral medium, the main decay channels of ABA- triplet state, the ABA• radical, and eaq- are T-T annihilation, recombination, and capture by the ABA- anion, respectively.

  18. Dissociative electron attachments to ethanol and acetaldehyde: A combined experimental and simulation study

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wang, Xu-Dong; Xuan, Chuan-Jin; Feng, Wen-Ling

    Dissociation dynamics of the temporary negative ions of ethanol and acetaldehyde formed by the low-energy electron attachments is investigated by using the anion velocity map imaging technique and ab initio molecular dynamics simulations. The momentum images of the dominant fragments O{sup −}/OH{sup −} and CH{sub 3}{sup −} are recorded, indicating the low kinetic energies of O{sup −}/OH{sup −} for ethanol while the low and high kinetic energy distributions of O{sup −} ions for acetaldehyde. The CH{sub 3}{sup −} image for acetaldehyde also shows the low kinetic energy. With help of the dynamics simulations, the fragmentation processes are qualitatively clarified. Amore » new cascade dissociation pathway to produce the slow O{sup −} ion via the dehydrogenated intermediate, CH{sub 3}CHO{sup −} (acetaldehyde anion), is proposed for the dissociative electron attachment to ethanol. After the electron attachment to acetaldehyde molecule, the slow CH{sub 3}{sup −} is produced quickly in the two-body dissociation with the internal energy redistributions in different aspects before bond cleavages.« less

  19. Temporary Assistance for Needy Families: Implications of Recent Legislative and Economic Changes for State Programs and Work Participation Rates. Report to Congressional Requesters. GAO-10-525

    ERIC Educational Resources Information Center

    Brown, Kay E.

    2010-01-01

    The Deficit Reduction Act of 2005 (DRA) reauthorized the Temporary Assistance for Needy Families (TANF) block grant and made modifications expected to strengthen work requirements for families receiving cash assistance through state TANF programs. Both the U.S. Department of Health and Human Services (HHS) and states were required to take steps to…

  20. Slow Photoelectron Velocity-Map Imaging of Cryogenically Cooled Anions

    NASA Astrophysics Data System (ADS)

    Weichman, Marissa L.; Neumark, Daniel M.

    2018-04-01

    Slow photoelectron velocity-map imaging spectroscopy of cryogenically cooled anions (cryo-SEVI) is a powerful technique for elucidating the vibrational and electronic structure of neutral radicals, clusters, and reaction transition states. SEVI is a high-resolution variant of anion photoelectron spectroscopy based on photoelectron imaging that yields spectra with energy resolution as high as 1-2 cm‑1. The preparation of cryogenically cold anions largely eliminates hot bands and dramatically narrows the rotational envelopes of spectral features, enabling the acquisition of well-resolved photoelectron spectra for complex and spectroscopically challenging species. We review the basis and history of the SEVI method, including recent experimental developments that have improved its resolution and versatility. We then survey recent SEVI studies to demonstrate the utility of this technique in the spectroscopy of aromatic radicals, metal and metal oxide clusters, nonadiabatic interactions between excited states of small molecules, and transition states of benchmark bimolecular reactions.

  1. TDDFT study on the sensing mechanism of a fluorescent sensor for fluoride anion: Inhibition of the ESPT process.

    PubMed

    Li, Guang-Yue; Liu, Dong; Zhang, Hang; Li, Wei-Wei; Wang, Feng; Liang, Ying-Hua

    2015-01-01

    The fluoride-sensing mechanism of a reported salicylaldehyde-based sensor (J. Photochem. Photobiol. B 2014, 138, 75) has been investigated by the TDDFT method. The present theoretical study indicates that there is an excited-state proton transfer (ESPT) process from the phenolic O-H moiety to the neighbor N atom in the sensor. The added fluoride anion could capture the proton in the O-H moiety and the corresponding phenolic anion is formed, which could inhibit the ESPT process. The experimental UV/Vis and fluorescence spectra are well reproduced by the calculated vertical excitation energies. Frontier molecular orbital analysis indicates that the local excited state of phenolic anion is responsible for its enhanced fluorescence. Due to this reason, the sensor can be used to sense fluoride anion by monitoring the fluorescent change. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Expanding frontiers in materials chemistry and physics with multiple anions.

    PubMed

    Kageyama, Hiroshi; Hayashi, Katsuro; Maeda, Kazuhiko; Attfield, J Paul; Hiroi, Zenji; Rondinelli, James M; Poeppelmeier, Kenneth R

    2018-02-22

    During the last century, inorganic oxide compounds laid foundations for materials synthesis, characterization, and technology translation by adding new functions into devices previously dominated by main-group element semiconductor compounds. Today, compounds with multiple anions beyond the single-oxide ion, such as oxyhalides and oxyhydrides, offer a new materials platform from which superior functionality may arise. Here we review the recent progress, status, and future prospects and challenges facing the development and deployment of mixed-anion compounds, focusing mainly on oxide-derived materials. We devote attention to the crucial roles that multiple anions play during synthesis, characterization, and in the physical properties of these materials. We discuss the opportunities enabled by recent advances in synthetic approaches for design of both local and overall structure, state-of-the-art characterization techniques to distinguish unique structural and chemical states, and chemical/physical properties emerging from the synergy of multiple anions for catalysis, energy conversion, and electronic materials.

  3. 26 CFR 1.25-1T - Credit for interest paid on certain home mortgages (Temporary).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 1 2010-04-01 2010-04-01 true Credit for interest paid on certain home... on certain home mortgages (Temporary). (a) In general. Section 25 permits States and political... District of Columbia. (ii) Mortgage credit certificates issued by or on behalf of any State or political...

  4. 26 CFR 1.25-1T - Credit for interest paid on certain home mortgages (Temporary).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 1 2011-04-01 2009-04-01 true Credit for interest paid on certain home... on certain home mortgages (Temporary). (a) In general. Section 25 permits States and political... District of Columbia. (ii) Mortgage credit certificates issued by or on behalf of any State or political...

  5. Drug Abuse Prevention: Report of the Temporary State Commission to Evaluate the Drug Laws.

    ERIC Educational Resources Information Center

    Betros, Emeel S.; And Others

    The findings and recommendations of the Temporary State Commission to Evaluate the Drug Laws, set forth in the introduction to this report, are based on questionnaires to prevention experts and professionals responsible for child and adolescent care, on communications with community agencies, and on statewide public hearings. The committee found…

  6. Principal component analysis and hydrochemical facies characterization to evaluate groundwater quality in Varahi river basin, Karnataka state, India

    NASA Astrophysics Data System (ADS)

    Ravikumar, P.; Somashekar, R. K.

    2017-05-01

    The present study envisages the importance of graphical representations like Piper trilinear diagram and Chadha's plot, respectively to determine variation in hydrochemical facies and understand the evolution of hydrochemical processes in the Varahi river basin. The analytical values obtained from the groundwater samples when plotted on Piper's and Chadha's plots revealed that the alkaline earth metals (Ca2+, Mg2+) are significantly dominant over the alkalis (Na+, K+), and the strong acidic anions (Cl-, SO4 2-) dominant over the weak acidic anions (CO3 2-, HCO3 -). Further, Piper trilinear diagram classified 93.48 % of the samples from the study area under Ca2+-Mg2+-Cl--SO4 2- type and only 6.52 % samples under Ca2+-Mg2+-HCO3 - type. Interestingly, Chadha's plot also demonstrated the dominance of reverse ion exchange water having permanent hardness (viz., Ca-Mg-Cl type) in majority of the samples over recharging water with temporary hardness (i.e., Ca-Mg-HCO3 type). Thus, evaluation of hydrochemical facies from both the plots highlighted the contribution from the reverse ion exchange processes in controlling geochemistry of groundwater in the study area. Further, PCA analysis yielded four principal components (PC1, PC2, PC3 and PC4) with higher eigen values of 1.0 or more, accounting for 65.55, 10.17, 6.88 and 6.52 % of the total variance, respectively. Consequently, majority of the physico-chemical parameters (87.5 %) loaded under PC1 and PC2 were having strong positive loading (>0.75) and these are mainly responsible for regulating the hydrochemistry of groundwater in the study area.

  7. Structure of cyano-anion ionic liquids: X-ray scattering and simulations.

    PubMed

    Dhungana, Kamal B; Faria, Luiz F O; Wu, Boning; Liang, Min; Ribeiro, Mauro C C; Margulis, Claudio J; Castner, Edward W

    2016-07-14

    Ionic liquids with cyano anions have long been used because of their unique combination of low-melting temperatures, reduced viscosities, and increased conductivities. Recently we have shown that cyano anions in ionic liquids are particularly interesting for their potential use as electron donors to excited state photo-acceptors [B. Wu et al., J. Phys. Chem. B 119, 14790-14799 (2015)]. Here we report on bulk structural and quantum mechanical results for a series of ionic liquids based on the 1-ethyl-3-methylimidazolium cation, paired with the following five cyano anions: SeCN(-), SCN(-), N(CN)2 (-), C(CN)3 (-), and B(CN)4 (-). By combining molecular dynamics simulations, high-energy X-ray scattering measurements, and periodic boundary condition DFT calculations, we are able to obtain a comprehensive description of the liquid landscape as well as the nature of the HOMO-LUMO states for these ionic liquids in the condensed phase. Features in the structure functions for these ionic liquids are somewhat different than the commonly observed adjacency, charge-charge, and polarity peaks, especially for the bulkiest B(CN)4 (-) anion. While the other four cyano-anion ionic liquids present an anionic HOMO, the one for Im2,1 (+)/B(CN)4 (-) is cationic.

  8. 78 FR 53643 - Wage Methodology for the Temporary Non-Agricultural Employment H-2B Program; Delay of Effective Date

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-30

    ... connection with a temporary labor certification for use in petitioning the Department of Homeland Security to... not affect the Interim Final Rule, 78 FR 24047, published on April 24, 2013, establishing the current... States (U.S.) workers recruited in connection with a temporary labor certification for use in petitioning...

  9. 26 CFR 1.103(n)-3T - Private activity bond limit (temporary).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 2 2011-04-01 2011-04-01 false Private activity bond limit (temporary). 1.103(n)-3T Section 1.103(n)-3T Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY....103(n)-3T Private activity bond limit (temporary). Q-1: What is the “State ceiling”? A-1: In general...

  10. 76 FR 7898 - Wheego Electric Cars, Inc.; Grant of Application for Temporary Exemption From Advanced Air Bag...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-11

    ...-0118] Wheego Electric Cars, Inc.; Grant of Application for Temporary Exemption From Advanced Air Bag... grants the petition of Wheego Electric Cars, Inc. (Wheego) for the temporary exemption of its Whip LiFe... manufacturer of a plug-in electric car. The stated basis of the petition was that requiring compliance would...

  11. 26 CFR 1.923-1T - Temporary regulations; exempt foreign trade income.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 10 2010-04-01 2010-04-01 false Temporary regulations; exempt foreign trade income. 1.923-1T Section 1.923-1T Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Earned Income of Citizens of United States § 1.923-1T Temporary regulations; exempt foreign trade...

  12. 26 CFR 1.923-1T - Temporary regulations; exempt foreign trade income.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 10 2012-04-01 2012-04-01 false Temporary regulations; exempt foreign trade income. 1.923-1T Section 1.923-1T Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Earned Income of Citizens of United States § 1.923-1T Temporary regulations; exempt...

  13. 26 CFR 1.103(n)-3T - Private activity bond limit (temporary).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 2 2010-04-01 2010-04-01 false Private activity bond limit (temporary). 1.103(n)-3T Section 1.103(n)-3T Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY....103(n)-3T Private activity bond limit (temporary). Q-1: What is the “State ceiling”? A-1: In general...

  14. Colorless to purple-red switching electrochromic anthraquinone imides with broad visible/near-IR absorptions in the radical anion state: simulation-aided molecular design.

    PubMed

    Chen, Fengkun; Zhang, Jie; Jiang, Hong; Wan, Xinhua

    2013-07-01

    The large redshift of near-infrared (NIR) absorptions of nitro-substituted anthraquinone imide (Nitro-AQI) radical anions, relative to other AQI derivatives, is rationalized based on quantum chemical calculations. Calculations reveal that the delocalization effects of electronegative substitution in the radical anion states is dramatically enhanced, thus leading to a significant decrease in the HOMO-LUMO band gap in the radical anion states. Based on this understanding, an AQI derivative with an even stronger electron-withdrawing dicyanovinyl (di-CN) substituent was designed and prepared. The resulting molecule, di-CN-AQI, displays no absorption in the Vis/NIR region in the neutral state, but absorbs intensively in the range of λ=700-1000 (λmax ≈860 nm) and λ=1100-1800 nm (λmax ≈1400 nm) upon one-electron reduction; this is accompanied by a transition from a highly transmissive colorless solution to one that is purple-red. The relationship between calculated radical anionic HOMO-LUMO gaps and the electron-withdrawing capacity of the substituents is also determined by employing Hammett parameter, which could serve as a theoretical tool for further molecular design. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. 20 CFR 655.76 - Appeal of administrative law judge decision.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... TEMPORARY EMPLOYMENT OF FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process and Enforcement of Attestations for Temporary Employment in Occupations Other Than Agriculture or Registered Nursing in the United...

  16. Microtitration of various anions with quaternary ammonium halides using solid-state electrodes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Selig, W.

    1980-01-01

    Many solid-state electrodes were found to respond as endpoint detectors in the potentiometric titration of large inorganic and organic anions with quaternary ammonium halides. The best response was obtained with the iodide and cyanide electrodes although practically any electrode can function as endpoint sensor. The titrants were hexadecylpyridinium chloride and hexadecyltrimethylammonium chloride; hexadecyltrimethylammonium bromide and Hyamine 1622 may also be used. Some inorganic anions thus titratable are perrhenate, persulfate, ferricyanide, hexafluorophosphate, and hexachloroplatinate. Examples of organic anions titratable are nitroform, tetraphenylborate, cyanotriphenylborate, picrate, long-chain sulfates and sulfonates, and some soaps. The reverse titration of quaternary ammonium halides vs dodecylsulfate ismore » also feasible. Some titrations are feasible in a partially nonaqueous medium.« less

  17. Photophysics and photochemistry of 2-aminobenzoic acid anion in aqueous solution.

    PubMed

    Pozdnyakov, Ivan P; Plyusnin, Victor F; Grivin, Vjacheslav P

    2009-12-24

    Nanosecond laser flash photolysis and absorption and fluorescence spectroscopy were used to study photochemical processes of 2-aminobenzoic acid anion (ABA(-)) in aqueous solutions. Excitation of this species gives rise to the ABA(-) triplet state to the ABA* radical and to the hydrated electron (e(aq)(-)). The last two species result from two-photon processes. In a neutral medium, the main decay channels of ABA(-) triplet state, the ABA* radical, and e(aq)(-) are T-T annihilation, recombination, and capture by the ABA(-) anion, respectively.

  18. 19 CFR 210.44 - Commission review on its own motion of initial determinations on matters other than temporary...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 19 Customs Duties 3 2013-04-01 2013-04-01 false Commission review on its own motion of initial determinations on matters other than temporary relief. 210.44 Section 210.44 Customs Duties UNITED STATES... matters other than temporary relief. Within the time provided in § 210.43(d)(1), the Commission on its own...

  19. 19 CFR 210.44 - Commission review on its own motion of initial determinations on matters other than temporary...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 3 2011-04-01 2011-04-01 false Commission review on its own motion of initial determinations on matters other than temporary relief. 210.44 Section 210.44 Customs Duties UNITED STATES... matters other than temporary relief. Within the time provided in § 210.43(d)(1), the Commission on its own...

  20. 19 CFR 210.44 - Commission review on its own motion of initial determinations on matters other than temporary...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 3 2014-04-01 2014-04-01 false Commission review on its own motion of initial determinations on matters other than temporary relief. 210.44 Section 210.44 Customs Duties UNITED STATES... matters other than temporary relief. Within the time provided in § 210.43(d)(1), the Commission on its own...

  1. 19 CFR 210.44 - Commission review on its own motion of initial determinations on matters other than temporary...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 3 2012-04-01 2012-04-01 false Commission review on its own motion of initial determinations on matters other than temporary relief. 210.44 Section 210.44 Customs Duties UNITED STATES... matters other than temporary relief. Within the time provided in § 210.43(d)(1), the Commission on its own...

  2. 26 CFR 1.904(g)-1T - Overall domestic loss and the overall domestic loss account (temporary).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... loss account (temporary). 1.904(g)-1T Section 1.904(g)-1T Internal Revenue INTERNAL REVENUE SERVICE... United States § 1.904(g)-1T Overall domestic loss and the overall domestic loss account (temporary). (a... accounts for purposes of section 904(g). Section 1.904(g)-2T provides rules for recapturing the balance in...

  3. Permanent Visas and Temporary Jobs: Evidence from Postdoctoral Participation of Foreign PhDs in the United States

    ERIC Educational Resources Information Center

    Lan, Xiaohuan

    2012-01-01

    About 75 percent of U.S.-trained, noncitizen PhDs in science and engineering work in the United States after graduation, and 54 percent of those who stay take postdoctoral positions. The probability of postdoctoral participation is substantially higher for temporary visa holders than for permanent visa holders because of visa-related restrictions…

  4. 77 FR 10037 - Temporary Non-Agricultural Employment of H-2B Aliens in the United States

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-21

    ... Administration 20 CFR Part 655 Wage and Hour Division 29 CFR Part 503 Temporary Non-Agricultural Employment of H... Employment of H-2B Aliens in the United States AGENCY: Employment and Training Administration, and Wage and... nonimmigrant worker in H-2B status. We have also created new regulations to provide for increased worker...

  5. Chimera states in multi-strain epidemic models with temporary immunity

    NASA Astrophysics Data System (ADS)

    Bauer, Larissa; Bassett, Jason; Hövel, Philipp; Kyrychko, Yuliya N.; Blyuss, Konstantin B.

    2017-11-01

    We investigate a time-delayed epidemic model for multi-strain diseases with temporary immunity. In the absence of cross-immunity between strains, dynamics of each individual strain exhibit emergence and annihilation of limit cycles due to a Hopf bifurcation of the endemic equilibrium, and a saddle-node bifurcation of limit cycles depending on the time delay associated with duration of temporary immunity. Effects of all-to-all and non-local coupling topologies are systematically investigated by means of numerical simulations, and they suggest that cross-immunity is able to induce a diverse range of complex dynamical behaviors and synchronization patterns, including discrete traveling waves, solitary states, and amplitude chimeras. Interestingly, chimera states are observed for narrower cross-immunity kernels, which can have profound implications for understanding the dynamics of multi-strain diseases.

  6. Effectiveness study on temporary pavement marking removals methods.

    DOT National Transportation Integrated Search

    2011-06-01

    This study was conducted to identify effective temporary marking removal methods and procedures on concrete and asphalt pavements. Pavement markings provide guidance to road travelers and can lead to accidents when not properly removed. Current state...

  7. Molecular anions.

    PubMed

    Simons, Jack

    2008-07-24

    The experimental and theoretical study of molecular anions has undergone explosive growth over the past 40 years. Advances in techniques used to generate anions in appreciable numbers as well as new ion-storage, ion-optics, and laser spectroscopic tools have been key on the experimental front. Theoretical developments on the electronic structure and molecular dynamics fronts now allow one to achieve higher accuracy and to study electronically metastable states, thus bringing theory in close collaboration with experiment in this field. In this article, many of the experimental and theoretical challenges specific to studying molecular anions are discussed. Results from many research groups on several classes of molecular anions are overviewed, and both literature citations and active (in online html and pdf versions) links to numerous contributing scientists' Web sites are provided. Specific focus is made on the following families of anions: dipole-bound, zwitterion-bound, double-Rydberg, multiply charged, metastable, cluster-based, and biological anions. In discussing each kind of anion, emphasis is placed on the structural, energetic, spectroscopic, and chemical-reactivity characteristics that make these anions novel, interesting, and important.

  8. Lithium cluster anions: photoelectron spectroscopy and ab initio calculations.

    PubMed

    Alexandrova, Anastassia N; Boldyrev, Alexander I; Li, Xiang; Sarkas, Harry W; Hendricks, Jay H; Arnold, Susan T; Bowen, Kit H

    2011-01-28

    Structural and energetic properties of small, deceptively simple anionic clusters of lithium, Li(n)(-), n = 3-7, were determined using a combination of anion photoelectron spectroscopy and ab initio calculations. The most stable isomers of each of these anions, the ones most likely to contribute to the photoelectron spectra, were found using the gradient embedded genetic algorithm program. Subsequently, state-of-the-art ab initio techniques, including time-dependent density functional theory, coupled cluster, and multireference configurational interactions methods, were employed to interpret the experimental spectra.

  9. Stabilization of very rare tautomers of 1-methylcytosine by an excess electron.

    PubMed

    Harańczyk, Maciej; Rak, Janusz; Gutowski, Maciej

    2005-12-22

    We characterized valence anionic states of 1-methylcytosine using various electronic structure methods. We found that the most stable valence anion is related to neither the canonical amino-oxo nor a rare imino-oxo tautomer, in which a proton is transferred from the N4 to N3 atom. Instead, it is related to an imino-oxo tautomer, in which the C5 atom is protonated. This anion is characterized by an electron vertical detachment energy (VDE) of 2.12 eV and it is more stable than the anion based on the canonical tautomer by 1.0 kcal/mol. The latter is characterized by a VDE of 0.31 eV. Another unusual low-lying imino-oxo tautomer with a VDE of 3.60 eV has the C6 atom protonated and is 3.6 kcal/mol less stable than the anion of the canonical tautomer. All these anionic states are adiabatically unbound with respect to the canonical amino-oxo neutral, with the instability of 5.8 kcal/mol for the most stable valence anion. The mechanism of formation of anionic tautomers with carbon atoms protonated may involve intermolecular proton transfer or dissociative electron attachment to the canonical neutral tautomer followed by a barrier-free attachment of a hydrogen atom to the C5 or C6 atom. The six-member ring structure of anionic tautomers with carbon atoms protonated is unstable upon an excess electron detachment. Indeed the neutral systems collapse without a barrier to a linear or a bicyclo structure, which might be viewed as lesions to DNA or RNA. Within the PCM hydration model, the anions become adiabatically bound with respect to the corresponding neutrals, and the two most stable tautomers have a carbon atom protonated.

  10. 26 CFR 1.103(n)-7T - Election to allocate State ceiling to certain facilities for local furnishing of electricity...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 2 2012-04-01 2012-04-01 false Election to allocate State ceiling to certain facilities for local furnishing of electricity (temporary). 1.103(n)-7T Section 1.103(n)-7T Internal Revenue... certain facilities for local furnishing of electricity (temporary). (a) Election—(1) In general. The...

  11. 26 CFR 1.103(n)-7T - Election to allocate State ceiling to certain facilities for local furnishing of electricity...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 2 2010-04-01 2010-04-01 false Election to allocate State ceiling to certain facilities for local furnishing of electricity (temporary). 1.103(n)-7T Section 1.103(n)-7T Internal Revenue... certain facilities for local furnishing of electricity (temporary). (a) Election—(1) In general. The...

  12. 26 CFR 1.103(n)-7T - Election to allocate State ceiling to certain facilities for local furnishing of electricity...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 2 2014-04-01 2014-04-01 false Election to allocate State ceiling to certain facilities for local furnishing of electricity (temporary). 1.103(n)-7T Section 1.103(n)-7T Internal Revenue... certain facilities for local furnishing of electricity (temporary). (a) Election—(1) In general. The...

  13. 26 CFR 1.103(n)-7T - Election to allocate State ceiling to certain facilities for local furnishing of electricity...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 2 2013-04-01 2013-04-01 false Election to allocate State ceiling to certain facilities for local furnishing of electricity (temporary). 1.103(n)-7T Section 1.103(n)-7T Internal Revenue... certain facilities for local furnishing of electricity (temporary). (a) Election—(1) In general. The...

  14. 26 CFR 1.103(n)-7T - Election to allocate State ceiling to certain facilities for local furnishing of electricity...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 2 2011-04-01 2011-04-01 false Election to allocate State ceiling to certain facilities for local furnishing of electricity (temporary). 1.103(n)-7T Section 1.103(n)-7T Internal Revenue... certain facilities for local furnishing of electricity (temporary). (a) Election—(1) In general. The...

  15. 26 CFR 1.956-3T - Certain trade or service receivables acquired from United States persons (temporary).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 10 2012-04-01 2012-04-01 false Certain trade or service receivables acquired from United States persons (temporary). 1.956-3T Section 1.956-3T Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Controlled Foreign Corporations § 1.956-3T Certain...

  16. Observation of Excited Quadrupole-Bound States in Cold Anions

    NASA Astrophysics Data System (ADS)

    Zhu, Guo-Zhu; Liu, Yuan; Wang, Lai-Sheng

    2017-07-01

    We report the first observation of an excited quadrupole-bound state (QBS) in an anion. High-resolution photoelectron imaging of cryogenically cooled 4-cyanophenoxide (4 CP- ) anions yields an electron detachment threshold of 24 927 cm-1 . The photodetachment spectrum reveals a resonant transition 20 cm-1 below the detachment threshold, which is attributed to an excited QBS of 4 CP- because neutral 4CP has a large quadrupole moment with a negligible dipole moment. The QBS is confirmed by observation of seventeen above-threshold resonances due to autodetachment from vibrational levels of the QBS.

  17. Hole localization, migration, and the formation of peroxide anion in perovskite SrTiO3

    NASA Astrophysics Data System (ADS)

    Chen, Hungru; Umezawa, Naoto

    2014-07-01

    Hybrid density functional calculations are carried out to investigate the behavior of holes in SrTiO3. As in many other oxides, it is shown that a hole tend to localize on one oxygen forming an O- anion with a concomitant lattice distortion; therefore a hole polaron. The calculated emission energy from the recombination of the localized hole and a conduction-band electron is about 2.5 eV, in good agreement with experiments. Therefore the localization of the hole or self-trapping is likely to be responsible for the green photoluminescence at low temperature, which was previously attributed to an unknown defect state. Compared to an electron, the calculated hole polaron mobility is three orders of magnitude lower at room temperature. In addition, two O- anions can bind strongly to form an O22- peroxide anion. No electronic states associated with the O22- peroxide anion are located inside the band gap or close to the band edges, indicating that it is electronically inactive. We suggest that in addition to the oxygen vacancy, the formation of the O22- peroxide anion can be an alternative to compensate acceptor doping in SrTiO3.

  18. Native aggregation as a cause of origin of temporary cellular structures needed for all forms of cellular activity, signaling and transformations.

    PubMed

    Matveev, Vladimir V

    2010-06-09

    According to the hypothesis explored in this paper, native aggregation is genetically controlled (programmed) reversible aggregation that occurs when interacting proteins form new temporary structures through highly specific interactions. It is assumed that Anfinsen's dogma may be extended to protein aggregation: composition and amino acid sequence determine not only the secondary and tertiary structure of single protein, but also the structure of protein aggregates (associates). Cell function is considered as a transition between two states (two states model), the resting state and state of activity (this applies to the cell as a whole and to its individual structures). In the resting state, the key proteins are found in the following inactive forms: natively unfolded and globular. When the cell is activated, secondary structures appear in natively unfolded proteins (including unfolded regions in other proteins), and globular proteins begin to melt and their secondary structures become available for interaction with the secondary structures of other proteins. These temporary secondary structures provide a means for highly specific interactions between proteins. As a result, native aggregation creates temporary structures necessary for cell activity."One of the principal objects of theoretical research in any department of knowledge is to find the point of view from which the subject appears in its greatest simplicity."Josiah Willard Gibbs (1839-1903).

  19. Regulations of 28 April 1989 on the issuance of visas.

    PubMed

    1989-01-01

    These Venezuelan Regulations set forth the rules on the issuance of tourist visas, temporary visas, temporary business visas, temporary student visas, temporary labor visas, and transit visas. In order to obtain a tourist visa a person must have a passport and in certain cases be able to prove that he or she has sufficient financial resources to cover the costs of staying in Venezuela. In order to obtain a temporary visa a person must have a passport, an officially certified police record, proof of civil status, and proof of a satisfactory medical examination. In order to obtain a temporary business visa a person must have a passport, documents proving his or her business objectives, and, when applicable, documents showing that he or she owns a business. In order to obtain a temporary student visa a person must have a passport, proof of sufficient economic resources, proof of a satisfactory medical examination, and documents attesting admittance to an educational program; he or she must also state that he will not engage in paid activities. In order to obtain a temporary labor visa a person must have documents proving employment, a document from the business or person employing him or her stating that it will cover the costs of the person's residence and departure, proof of satisfactory medical examination, and an officially certified police record; in addition, the employer must ask the authorities for permission to hire him or her. In order to obtain a transit visa a person must have a passport, confirmed passage to a 3rd country, and transportation documents. This visa is valid for 72 hours; all other visas are valid for 1 year.

  20. Tuberculosis Among Temporary Visa Holders Working in the Tourism Industry - United States, 2012-2014.

    PubMed

    Weinberg, Meghan P; Cherry, Cara; Lipnitz, Julie; Nienstadt, Linus; King-Todd, April; Haddad, Maryam B; Russell, Michelle; Wong, David; Davidson, Peter; McFadden, Jevon; Miller, Corinne

    2016-03-25

    Tuberculosis (TB) is a contagious bacterial disease of global concern. During 2013, an estimated nine million incident TB cases occurred worldwide (1). The majority (82%) were diagnosed in 22 countries, including South Africa and the Philippines, where annual incidence was 860 TB cases per 100,000 persons and 292 TB cases per 100,000 persons, respectively (1). The 2013 TB incidence in the United States was three cases per 100,000 persons (2). Under the Immigration and Nationality Act, TB screening is required for persons seeking permanent residence in the United States (i.e., immigrants and refugees), but it is not routinely required for nonimmigrants who are issued temporary visas for school or work (3). A portion of the U.S. tourism industry relies on temporary visa holders to accommodate seasonal and fluctuating demand for service personnel (4). This report describes three foreign-born persons holding temporary visas who had infectious TB while working at tourist destinations in the United States during 2012-2014. Multiple factors, including dormitory-style housing, transient work patterns, and diagnostic delays might have contributed to increased opportunity for TB transmission. Clinicians in seasonally driven tourist destinations should be aware of the potential for imported TB disease in foreign-born seasonal workers and promptly report suspected cases to health officials.

  1. The electrostatics of VDAC: implications for selectivity and gating.

    PubMed

    Choudhary, Om P; Ujwal, Rachna; Kowallis, William; Coalson, Rob; Abramson, Jeff; Grabe, Michael

    2010-02-26

    The voltage-dependent anion channel (VDAC) is the major pathway mediating the transfer of metabolites and ions across the mitochondrial outer membrane. Two hallmarks of the channel in the open state are high metabolite flux and anion selectivity, while the partially closed state blocks metabolites and is cation selective. Here we report the results from electrostatics calculations carried out on the recently determined high-resolution structure of murine VDAC1 (mVDAC1). Poisson-Boltzmann calculations show that the ion transfer free energy through the channel is favorable for anions, suggesting that mVDAC1 represents the open state. This claim is buttressed by Poisson-Nernst-Planck calculations that predict a high single-channel conductance indicative of the open state and an anion selectivity of 1.75--nearly a twofold selectivity for anions over cations. These calculations were repeated on mutant channels and gave selectivity changes in accord with experimental observations. We were then able to engineer an in silico mutant channel with three point mutations that converted mVDAC1 into a channel with a preference for cations. Finally, we investigated two proposals for how the channel gates between the open and the closed state. Both models involve the movement of the N-terminal helix, but neither motion produced the observed voltage sensitivity, nor did either model result in a cation-selective channel, which is observed experimentally. Thus, we were able to rule out certain models for channel gating, but the true motion has yet to be determined. Copyright (c) 2009. Elsevier Ltd. All rights reserved.

  2. Positronium hydride in hydrogen-laden thermochemically reduced MgO single crystals

    NASA Astrophysics Data System (ADS)

    Pareja, R.; de La Cruz, R. M.; Pedrosa, M. A.; González, R.; Chen, Y.

    1990-04-01

    Thermochemical reduction of hydrogen-laden MgO single crystals at T~2400 K results in a large concentration of both hydride (H-) ions and anion vacancies (>1024 m-3). Positron-lifetime experiments of these crystals provide evidence for bound positronium hydride states also referred to as [e+-H-] or PsH states. The presence of the anion vacancies was found to inhibit the formation of these states. After thermally annealing out these vacancies, such that H- concentration remains intact, two long-lived components appear in the lifetime spectrum. Furthermore, these two components correlate with the presence of the H-ions. These results suggest the existence of bound [e+-H-] states when positrons are trapped by the H- ions, and the subsequent formation of positronium (Ps) states by the dissociation of the [e+-H-] states. From the values of the intermediate lifetime component, a value of (570+/-50) ps is obtained for the lifetime of the PsH state located in an anion vacancy in MgO. The longest lifetime component ~(1-3) ns is attributed to pick-off annihilation of ortho-Ps states.

  3. Structure of cyano-anion ionic liquids: X-ray scattering and simulations

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dhungana, Kamal B.; Faria, Luiz F. O.; Wu, Boning

    2016-07-14

    Ionic liquids with cyano anions have long been used because of their unique combination of low-melting temperatures, reduced viscosities, and increased conductivities. Recently we have shown that cyano anions in ionic liquids are particularly interesting for their potential use as electron donors to excited state photo-acceptors [B. Wu et al., J. Phys. Chem. B 119, 14790–14799 (2015)]. Here we report on bulk structural and quantum mechanical results for a series of ionic liquids based on the 1-ethyl-3-methylimidazolium cation, paired with the following five cyano anions: SeCN-, SCN-, N(CN)-2N(CN)2-, C(CN)-3C(CN)3-, and B(CN)-4B(CN)4-. By combining molecular dynamics simulations, high-energy X-ray scattering measurements,more » and periodic boundary condition DFT calculations, we are able to obtain a comprehensive description of the liquid landscape as well as the nature of the HOMO-LUMO states for these ionic liquids in the condensed phase. Features in the structure functions for these ionic liquids are somewhat different than the commonly observed adjacency, charge-charge, and polarity peaks, especially for the bulkiest B(CN)-4B(CN)4- anion. While the other four cyano-anion ionic liquids present an anionic HOMO, the one for Im+2,1Im2,1+/B(CN)-4B(CN)4- is cationic.« less

  4. Unusual structures of MgF5- superhalogen anion

    NASA Astrophysics Data System (ADS)

    Anusiewicz, Iwona; Skurski, Piotr

    2007-05-01

    The vertical electron detachment energies (VDE) of three MgF5- anions were calculated at the outer valence Green function level with the 6-311 + G(3df) basis sets. This species was found to form unusual geometrical structures each of which corresponds to an anionic state exhibiting superhalogen nature. The global minimum structure was described as a system in which two central magnesium atoms are linked via symmetrical triangle formed by three fluorine atoms. Extremely large electron binding energies of these anions (exceeding 8.5 eV in all cases) were predicted and discussed.

  5. Inhibition of Radiolytic Molecular Hydrogen Formation by Quenching of Excited State Water

    DOE PAGES

    Horne, Gregory P.; Pimblott, Simon M.; LaVerne, Jay A.

    2017-05-11

    Comparison of experimental measurements of the yield of molecular hydrogen produced in the gamma radiolysis of water and aqueous nitrate solutions with predictions of a Monte Carlo track chemistry model shows that the nitrate anion scavenging of the hydrated electron, its precursor, and hydrogen atom cannot account for the observed decrease in the yield at high nitrate anion concentrations. Inclusion of the quenching of excited states of water (formed by either direct excitation or reaction of the water radical cation with the precursor to the hydrated electron) by the nitrate anion into the reaction scheme provides excellent agreement between themore » stochastic calculations and experiment demonstrating the existence of this short-lived species and its importance in water radiolysis. Energy transfer from the excited states of water to the nitrate anion producing an excited state provides an additional pathway for the production of nitrogen containing products not accounted for in traditional radiation chemistry scenarios. Such reactions are of central importance in predicting the behavior of liquors common in the reprocessing of spent nuclear fuel and the storage of highly radioactive liquid waste prior to vitrification.« less

  6. 8 CFR 1244.18 - Issuance of charging documents; detention.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... seek such a waiver in deportation or exclusion proceedings. The charging document shall constitute... JUSTICE IMMIGRATION REGULATIONS TEMPORARY PROTECTED STATUS FOR NATIONALS OF DESIGNATED STATES § 1244.18... of deportation or exclusion against an alien granted Temporary Protected Status shall constitute a...

  7. 77 FR 12883 - Announcement of Public Briefings on the Changes to the Labor Certification Process for the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-02

    ... Employment of H-2B Aliens in the United States AGENCIES: Employment and Training Administration and Wage and... temporary or seasonal non-agricultural employment. See Temporary Non-Agricultural Employment of H-2B Aliens...

  8. 29 CFR 1952.104 - Final approval determination.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... OSHA through participation in the Federal-state Integrated Management Information System, the Assistant... exception of temporary labor camps in agriculture, general industry, construction and logging) is at least... covered by the plan (with the exception of temporary labor camps in agriculture, general industry...

  9. Anion photoelectron spectroscopy of radicals and clusters

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Travis, Taylor R.

    1999-12-01

    Anion photoelectron spectroscopy is used to study free radicals and clusters. The low-lying 2Σ and 2π states of C 2nH (n = 1--4) have been studied. The anion photoelectron spectra yielded electron affinities, term values, and vibrational frequencies for these combustion and astrophysically relevant species. Photoelectron angular distributions allowed the author to correctly assign the electronic symmetry of the ground and first excited states and to assess the degree of vibronic coupling in C 2H and C 4H. Other radicals studied include NCN and I 3. The author was able to observe the low-lying singlet and triplet states of NCNmore » for the first time. Measurement of the electron affinity of I 3 revealed that it has a bound ground state and attachment of an argon atom to this moiety enabled him to resolve the symmetric stretching progression.« less

  10. A biological tool to assess flow connectivity in reference temporary streams from the Mediterranean Basin.

    PubMed

    Cid, N; Verkaik, I; García-Roger, E M; Rieradevall, M; Bonada, N; Sánchez-Montoya, M M; Gómez, R; Suárez, M L; Vidal-Abarca, M R; Demartini, D; Buffagni, A; Erba, S; Karaouzas, I; Skoulikidis, N; Prat, N

    2016-01-01

    Many streams in the Mediterranean Basin have temporary flow regimes. While timing for seasonal drought is predictable, they undergo strong inter-annual variability in flow intensity. This high hydrological variability and associated ecological responses challenge the ecological status assessment of temporary streams, particularly when setting reference conditions. This study examined the effects of flow connectivity in aquatic macroinvertebrates from seven reference temporary streams across the Mediterranean Basin where hydrological variability and flow conditions are well studied. We tested for the effect of flow cessation on two streamflow indices and on community composition, and, by performing random forest and classification tree analyses we identified important biological predictors for classifying the aquatic state either as flowing or disconnected pools. Flow cessation was critical for one of the streamflow indices studied and for community composition. Macroinvertebrate families found to be important for classifying the aquatic state were Hydrophilidae, Simuliidae, Hydropsychidae, Planorbiidae, Heptageniidae and Gerridae. For biological traits, trait categories associated to feeding habits, food, locomotion and substrate relation were the most important and provided more accurate predictions compared to taxonomy. A combination of selected metrics and associated thresholds based on the most important biological predictors (i.e. Bio-AS Tool) were proposed in order to assess the aquatic state in reference temporary streams, especially in the absence of hydrological data. Although further development is needed, the tool can be of particular interest for monitoring, restoration, and conservation purposes, representing an important step towards an adequate management of temporary rivers not only in the Mediterranean Basin but also in other regions vulnerable to the effects of climate change. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Perrhenate incorporation into binary mixed sodalites: The role of anion size and implications for technetium-99 sequestration

    DOE PAGES

    Dickson, Johnbull O.; Harsh, James B.; Lukens, Wayne W.; ...

    2014-12-20

    Perrhenate (ReO 4 -), as a TcO 4 - analogue, was incorporated into mixed-anion sodalites from binary solutions containing ReO 4 - and a competing anion X n- (Cl -, CO 3 2-, SO 4 2-, MnO 4 -, or WO 4 2-). For this study, our objective was to determine the extent of solid solution formation and the dependence of competing ion selectivity on ion size. Using equivalent aqueous concentrations of the anions (ReO 4 -/X n- molar ratio = 1:1), we synthesized mixed-anion sodalites from zeolite and NaOH at 90 °C for 96 h. The resulting solids weremore » characterized by bulk chemical analysis, powder X-ray diffraction, scanning electron microscopy, and X-ray absorption near edge structure (XANES) spectroscopy to determine crystal structure, chemical composition, morphology, and rhenium (Re) oxidation state. Rhenium in the solid phase occurred predominately as Re(VII)O 4 - in the sodalites, which have a primitive cubic pattern in the space group P43n. The refined unit-cell parameters of the mixed sodalites ranged from 8.88 to 9.15 Å and showed a linear dependence on the size and mole fraction of the incorporated anion(s). The ReO 4 - selectivity, represented by its distribution coefficient (K d), increased in the following order: Cl - < NO 3 - < MnO 4 - and CO 3 2- < SO 4 2- < WO 4 2- for the monovalent and divalent anions, respectively. The relationship between the ReO 4 - distribution coefficient and competing anion size was nonlinear. When the difference in ionic radius (DIR) between ReO 4 - and X n - (n = 1 or 2) was greater than ~ 12%, then ReO 4 - incorporation into sodalite was insignificant. The results imply that anion size is the major factor that determines sodalite anion compositions. Given the similarity in chemical behavior and anion size, ReO 4 - serves as a suitable analogue for TcO 4 - under oxidizing conditions where both elements are expected to remain as oxyanions in the + 7 oxidation state.« less

  12. Solid state oxygen anion and electron mediating membrane and catalytic membrane reactors containing them

    DOEpatents

    Schwartz, Michael; White, James H.; Sammells, Anthony F.

    2005-09-27

    This invention relates to gas-impermeable, solid state materials fabricated into membranes for use in catalytic membrane reactors. This invention particularly relates to solid state oxygen anion- and electron-mediating membranes for use in catalytic membrane reactors for promoting partial or full oxidation of different chemical species, for decomposition of oxygen-containing species, and for separation of oxygen from other gases. Solid state materials for use in the membranes of this invention include mixed metal oxide compounds having the brownmillerite crystal structure.

  13. Solid state oxygen anion and electron mediating membrane and catalytic membrane reactors containing them

    DOEpatents

    Schwartz, Michael; White, James H.; Sammels, Anthony F.

    2000-01-01

    This invention relates to gas-impermeable, solid state materials fabricated into membranes for use in catalytic membrane reactors. This invention particularly relates to solid state oxygen anion- and electron-mediating membranes for use in catalytic membrane reactors for promoting partial or full oxidation of different chemical species, for decomposition of oxygen-containing species, and for separation of oxygen from other gases. Solid state materials for use in the membranes of this invention include mixed metal oxide compounds having the brownmillerite crystal structure.

  14. 8 CFR 244.4 - Ineligible aliens.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 8 Aliens and Nationality 1 2013-01-01 2013-01-01 false Ineligible aliens. 244.4 Section 244.4 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS TEMPORARY PROTECTED STATUS FOR NATIONALS OF DESIGNATED STATES § 244.4 Ineligible aliens. An alien is ineligible for Temporary...

  15. 8 CFR 244.4 - Ineligible aliens.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 8 Aliens and Nationality 1 2011-01-01 2011-01-01 false Ineligible aliens. 244.4 Section 244.4 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS TEMPORARY PROTECTED STATUS FOR NATIONALS OF DESIGNATED STATES § 244.4 Ineligible aliens. An alien is ineligible for Temporary...

  16. 8 CFR 244.4 - Ineligible aliens.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 8 Aliens and Nationality 1 2012-01-01 2012-01-01 false Ineligible aliens. 244.4 Section 244.4 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS TEMPORARY PROTECTED STATUS FOR NATIONALS OF DESIGNATED STATES § 244.4 Ineligible aliens. An alien is ineligible for Temporary...

  17. 8 CFR 244.4 - Ineligible aliens.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Ineligible aliens. 244.4 Section 244.4 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS TEMPORARY PROTECTED STATUS FOR NATIONALS OF DESIGNATED STATES § 244.4 Ineligible aliens. An alien is ineligible for Temporary...

  18. 8 CFR 244.4 - Ineligible aliens.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 8 Aliens and Nationality 1 2014-01-01 2014-01-01 false Ineligible aliens. 244.4 Section 244.4 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS TEMPORARY PROTECTED STATUS FOR NATIONALS OF DESIGNATED STATES § 244.4 Ineligible aliens. An alien is ineligible for Temporary...

  19. 20 CFR 655.1 - Purpose and scope of subpart A.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... EMPLOYMENT OF FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process and Enforcement of Attestations for Temporary Employment in Occupations Other Than Agriculture or Registered Nursing in the United... governing the labor certification process for the temporary employment of nonimmigrant foreign workers in...

  20. Dynamic evaluation of a pinned anchoring system for New York state's temporary concrete barriers--phase II.

    DOT National Transportation Integrated Search

    2010-01-27

    Temporary concrete barrier (TCB) systems are utilized in many situations, including placement adjacent to vertical drop-offs. : Free-standing TCB systems are known to have relatively large deflections when impacted, which may be undesirable when deal...

  1. Self-Rated Health of the Temporary Employees in a Nordic Welfare State: Findings From the Finnish Public Sector Study.

    PubMed

    Virtanen, Pekka; Pentti, Jaana; Vahtera, Jussi; Kivimäki, Mika; Virtanen, Marianna

    2018-02-01

    This 9-year follow-up study explores a possible association between temporary employment and declining health. Years in temporary employment from 2004 to 2008 to 2009 were measured for a cohort of 26,886 public sector employees. Self-rated health was measured by surveys in 2004 (baseline), 2008/2009 (short-term follow-up), and 2012/2013 (long-term follow-up). Compared with the permanently employed, the baseline health-adjusted odds of poor health were lower both in the short-term and long-term follow-up, but the differences became nonsignificant when adjusted for sociodemographic and work-related factors. The results would suggest that temporary employment in public sector of a Nordic welfare state does not entail health risks. Future research is needed to elucidate if this is true also among those exposed to nonpermanent employment in the private labor market, in particular those with most atypical jobs and unstable job careers.

  2. Importance of counteranions on the hydration structure of the curium ion

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Atta Fynn, Raymond; Bylaska, Eric J.; De Jong, Wibe A.

    2013-07-04

    Using density functional theory based ab initio molecular dynamics and metadynamics we show that counter ions can trigger noticeable changes in the hydration shell structure of the curium ion. The free energies of curium-water coordination and the solvent hydrogen bond (HB) lifetimes in the absence and presence the counter anions predict that chloride and bromide counter anions strengthen the first shell and consequently the 8-fold coordination state is dominant by at least 98%. In contrast, the perchlorate counter anions are found to weaken the coordination shell and the HB network, with the 9-fold and 8-fold states existing in an 8:1more » ratio, which is in good agreement with reported 9:1 ratio seen in time resolved fluorescence spectroscopy experiments. To our knowledge this is the first time molecular simulations have shown that counter anions can directly affect the first hydration shell structure of a cation.« less

  3. Hydrogen anion and subgap states in amorphous In-Ga-Zn-O thin films for TFT applications

    NASA Astrophysics Data System (ADS)

    Bang, Joonho; Matsuishi, Satoru; Hosono, Hideo

    2017-06-01

    Hydrogen is an impurity species having an important role in the physical properties of semiconductors. Despite numerous studies, the role of hydrogen in oxide semiconductors remains an unsolved puzzle. This situation arises from insufficient information about the chemical state of the impurity hydrogen. Here, we report direct evidence for anionic hydrogens bonding to metal cations in amorphous In-Ga-Zn-O (a-IGZO) thin films for thin-film transistors (TFT) applications and discuss how the hydrogen impurities affect the electronic structure of a-IGZO. Infrared absorption spectra of self-standing a-IGZO thin films prepared by sputtering reveal the presence of hydrogen anions as a main hydrogen species (concentration is ˜1020 cm-3) along with the hydrogens in the form of the hydroxyl groups (˜1020 cm-3). Density functional theory calculations show that bonds between these hydride ions with metal centers give rise to subgap states above the top of the valence band, implying a crucial role of anionic hydrogen in the negative bias illumination stress instability commonly observed in a-IGZO TFTs.

  4. Dynamical Jahn-Teller effect of fullerene anions

    NASA Astrophysics Data System (ADS)

    Liu, Dan; Iwahara, Naoya; Chibotaru, Liviu F.

    2018-03-01

    The dynamical Jahn-Teller effect of C60n - anions (n =1 -5) is studied using the numerical diagonalization of the linear pn⊗8 d Jahn-Teller Hamiltonian with the currently established coupling parameters. It is found that in all anions the Jahn-Teller effect stabilizes the low-spin states, resulting in the violation of Hund's rule. The energy gain due to the Jahn-Teller dynamics is found to be comparable to the static Jahn-Teller stabilization. The Jahn-Teller dynamics influences the thermodynamic properties via strong variation of the density of vibronic states with energy. Thus the large vibronic entropy in the low-spin states enhances the effective spin gap of C603 - quenching the spin crossover. From the calculations of the effective spin gap as a function of the Hund's rule coupling, we found that the latter should amount 40 ±5 meV in order to cope with the violation of Hund's rule and to reproduce the large spin gap. With the obtained numerical solutions, the matrix elements of electronic operators for the low-lying vibronic levels and the vibronic reduction factors are calculated for all anions.

  5. Anion-π Catalysis on Fullerenes.

    PubMed

    López-Andarias, Javier; Frontera, Antonio; Matile, Stefan

    2017-09-27

    Anion-π interactions on fullerenes are about as poorly explored as the use of fullerenes in catalysis. However, strong exchange-correlation contributions and the localized π holes on their surface promise unique selectivities. To elaborate on this promise, tertiary amines are attached nearby. Dependent on their positioning, the resulting stabilization of anionic transition states on fullerenes is shown to accelerate disfavored enolate addition and exo Diels-Alder reactions enantioselectively. The found selectivities are consistent with computational simulations, particularly concerning the discrimination of differently planarized and charge-delocalized enolate tautomers by anion-π interactions. Enolate-π interactions on fullerenes are much shorter than standard π-π interactions and anion-π interactions on planar surfaces, and alternative cation-π interactions are not observed. These findings open new perspectives with regard to anion-π interactions in general and the use of carbon allotropes in catalysis.

  6. A conformationally persistent pseudo-bicyclic guanidinium for anion coordination as stabilized by dual intramolecular hydrogen bonds

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Seipp, Charles A.; Williams, Neil J.; Bryantsev, Vyacheslav S.

    2015-11-30

    In this paper, the first example of a pseudo-bicyclic guanidinium ligand is reported. When bound to an anion, the N,N'-bis(2-pyridyl)guanidinium cation persistently adopts the planar α,α conformation featuring intramolecular N···H–N–H···N hydrogen bonds in the solid state, which facilitates crystallization of sulphate from aqueous mixtures of anions.

  7. 20 CFR 655.155 - Referrals of U.S. workers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Referrals of U.S. workers. 655.155 Section 655.155 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR TEMPORARY EMPLOYMENT OF FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process for Temporary Agricultural...

  8. 20 CFR 655.157 - Withholding of U.S. workers prohibited.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false Withholding of U.S. workers prohibited. 655.157 Section 655.157 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR TEMPORARY EMPLOYMENT OF FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process for Temporary...

  9. 20 CFR 655.155 - Referrals of U.S. workers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false Referrals of U.S. workers. 655.155 Section 655.155 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR TEMPORARY EMPLOYMENT OF FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process for Temporary Agricultural...

  10. 20 CFR 655.145 - Amendments to applications for temporary employment certification.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ..., DEPARTMENT OF LABOR TEMPORARY EMPLOYMENT OF FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process... percent for employers requesting less than 10 workers) without requiring an additional recruitment period for U.S. workers. Requests for increases above the percent prescribed, without additional recruitment...

  11. 22 CFR 123.25 - Amendments to licenses.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... approve an amendment to a license for permanent export, temporary export and temporary import of... Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS LICENSES FOR THE EXPORT OF... forwarder and the export does not involve technical data. A new license is required for these changes. Any...

  12. 22 CFR 123.25 - Amendments to licenses.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... approve an amendment to a license for permanent export, temporary export and temporary import of... Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS LICENSES FOR THE EXPORT OF... forwarder and the export does not involve technical data. A new license is required for these changes. Any...

  13. 20 CFR 655.5 - Purpose and scope of subpart A.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... EMPLOYMENT OF FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process and Enforcement of Attestations for Temporary Employment in Occupations Other Than Agriculture or Registered Nursing in the United... certification process for the temporary employment of nonimmigrant foreign workers in the U.S. in occupations...

  14. 42 CFR 455.470 - Temporary moratoria.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... imposition of temporary moratoria on enrollment of new providers or provider types prior to imposition of the... moratoria on enrollment of new providers or provider types identified by the Secretary as posing an... limits that the State Medicaid agency identifies as having a significant potential for fraud, waste, or...

  15. 75 FR 70961 - 30-Day Notice of Proposed Information Collection: Voluntary Disclosures

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-19

    ... message. Fax: 202-395-5806. Attention: Desk Officer for Department of State. FOR FURTHER INFORMATION... collection: The export, temporary import, temporary export and brokering of defense articles, defense... of the Arms Export Control Act (AECA). Those who manufacture or export defense articles, defense...

  16. Dynamic evaluation of a pinned anchoring system for New York state's temporary concrete barriers : final report, September 8, 2009.

    DOT National Transportation Integrated Search

    2009-09-08

    Temporary concrete barrier (TCB) systems are utilized in many circumstances, including for placement adjacent to vertical : dropoffs. Free-standing TCB systems are known to have relatively large deflections when impacted, which may be undesirable whe...

  17. Configuration and energy landscape of the benzonitrile anion

    NASA Astrophysics Data System (ADS)

    Kirnosov, Nikita; Adamowicz, Ludwik

    2017-05-01

    Quantum chemical calculations are employed to study the configurational isomers of the anion formed by benzene substituted with a cyano group. It is found that an excess electron can form dipole-bound (DB) states with benzonitrile and phenyl-isocyanide isomers. It can also attach to the cyano group, if this group is separated from the benzene ring by some distance, forming a covalent CN- anion. There are four positions at peripherals of the benzene ring where this anion can localize and form stable complexes with the benzene radical. In these complexes CN- is connected to the benzene radical via non-covalent interactions.

  18. How people explain their own and others’ behavior: a theory of lay causal explanations

    PubMed Central

    Böhm, Gisela; Pfister, Hans-Rüdiger

    2015-01-01

    A theoretical model is proposed that specifies lay causal theories of behavior; and supporting experimental evidence is presented. The model’s basic assumption is that different types of behavior trigger different hypotheses concerning the types of causes that may have brought about the behavior. Seven categories are distinguished that are assumed to serve as both behavior types and explanation types: goals, dispositions, temporary states such as emotions, intentional actions, outcomes, events, and stimulus attributes. The model specifies inference rules that lay people use when explaining behavior (actions are caused by goals; goals are caused by higher order goals or temporary states; temporary states are caused by dispositions, stimulus attributes, or events; outcomes are caused by actions, temporary states, dispositions, stimulus attributes, or events; events are caused by dispositions or preceding events). Two experiments are reported. Experiment 1 showed that free-response explanations followed the assumed inference rules. Experiment 2 demonstrated that explanations which match the inference rules are generated faster and more frequently than non-matching explanations. Together, the findings support models that incorporate knowledge-based aspects into the process of causal explanation. The results are discussed with respect to their implications for different stages of this process, such as the activation of causal hypotheses and their subsequent selection, as well as with respect to social influences on this process. PMID:25741306

  19. Skilled temporary specialty workers in the United States.

    PubMed

    Lowell, B L

    1999-01-01

    This article lays some groundwork for understanding how the issues of supply play out in the US. This reviews the major categories of temporary visas and particularly considers the specialty H-1B visa. Basic requirements for the visa are discussed as well as the changes in the legislation. Data on temporary visas are incomplete. What exists is presented with an eye toward tracking changes in numbers since the Immigration Act of 1990 went into effect in 1992. The most recent data available as of this writing are for 1996. The article finishes with a short review of the research literature on the labor market impact of skilled immigrants. However, there is little research conducted on temporary workers.

  20. Anion-π Catalysts with Axial Chirality.

    PubMed

    Wang, Chao; Matile, Stefan

    2017-09-04

    The idea of anion-π catalysis is to stabilize anionic transition states by anion-π interactions on aromatic surfaces. For asymmetric anion-π catalysis, π-acidic surfaces have been surrounded with stereogenic centers. This manuscript introduces the first anion-π catalysts that operate with axial chirality. Bifunctional catalysts with tertiary amine bases next to π-acidic naphthalenediimide planes are equipped with a bulky aromatic substituent in the imide position to produce separable atropisomers. The addition of malonic acid half thioesters to enolate acceptors is used for evaluation. In the presence of a chiral axis, the selective acceleration of the disfavored but relevant enolate addition was much better than with point chirality, and enantioselectivity could be observed for the first time for this reaction with small-molecule anion-π catalysts. Enantioselectivity increased with the π acidity of the π surface, whereas the addition of stereogenic centers around the aromatic plane did not cause further improvements. These results identify axial chirality of the active aromatic plane generated by atropisomerism as an attractive strategy for asymmetric anion-π catalysis. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. 77 FR 12882 - Labor Certification Process for the Temporary Employment of Aliens in Agriculture in the United...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-02

    ... DEPARTMENT OF LABOR Employment and Training Administration Labor Certification Process for the Temporary Employment of Aliens in Agriculture in the United States: 2012 Allowable Charges for Agricultural Workers' Meals and Travel Subsistence Reimbursement, Including Lodging AGENCY: Employment and Training...

  2. 78 FR 15741 - Labor Certification Process for the Temporary Employment of Aliens in Agriculture in the United...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-12

    ... DEPARTMENT OF LABOR Employment and Training Administration Labor Certification Process for the Temporary Employment of Aliens in Agriculture in the United States: 2013 Allowable Charges for Agricultural Workers' Meals and Travel Subsistence Reimbursement, Including Lodging AGENCY: Employment and Training...

  3. 77 FR 13635 - Labor Certification Process for the Temporary Employment of Aliens in Agriculture in the United...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-07

    ... DEPARTMENT OF LABOR Employment and Training Administration Labor Certification Process for the Temporary Employment of Aliens in Agriculture in the United States: 2012 Allowable Charges for Agricultural Workers' Meals and Travel Subsistence Reimbursement, Including Lodging AGENCY: Employment and Training...

  4. 76 FR 11286 - Labor Certification Process for the Temporary Employment of Aliens in Agriculture in the United...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-01

    ... DEPARTMENT OF LABOR Employment and Training Administration Labor Certification Process for the Temporary Employment of Aliens in Agriculture in the United States: 2011 Adverse Effect Wage Rates, Allowable Charges for Agricultural Workers' Meals, and Maximum Travel Subsistence Reimbursement AGENCY...

  5. 78 FR 19019 - Labor Certification Process for the Temporary Employment of Aliens in Agriculture in the United...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-28

    ... DEPARTMENT OF LABOR Employment and Training Administration Labor Certification Process for the Temporary Employment of Aliens in Agriculture in the United States: Prevailing Wage Rates for Certain Occupations Processed Under H-2A Special Procedures; Correction and Rescission AGENCY: Employment and Training...

  6. 19 CFR 210.45 - Review of initial determinations on matters other than temporary relief.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 3 2010-04-01 2010-04-01 false Review of initial determinations on matters other than temporary relief. 210.45 Section 210.45 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Determinations and...

  7. 19 CFR 210.70 - Forfeiture or return of complainant's temporary relief bond.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... relief bond. 210.70 Section 210.70 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Temporary Relief § 210.70... and the Commission will be guided by practice under Rule 65 of the Federal Rules of Civil Procedure...

  8. 77 FR 58437 - 30-Day Notice of Proposed Information Collections: Two Directorate of Defense Trade Controls...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-20

    .... Attention: Desk Officer for Department of State. FOR FURTHER INFORMATION CONTACT: Direct requests for... proposed collection: The export, temporary import, temporary export and brokering of defense articles... articles, defense services, and related technical data, or the brokering thereof, must register with the...

  9. 22 CFR 41.53 - Temporary workers and trainees.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 41.53 Foreign Relations DEPARTMENT OF STATE VISAS VISAS: DOCUMENTATION OF NONIMMIGRANTS UNDER THE IMMIGRATION AND NATIONALITY ACT, AS AMENDED Business and Media Visas § 41.53 Temporary workers and trainees... alien is eligible to receive a nonimmigrant visa. (c) Validity of visa. The period of validity of a visa...

  10. 22 CFR 41.53 - Temporary workers and trainees.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 41.53 Foreign Relations DEPARTMENT OF STATE VISAS VISAS: DOCUMENTATION OF NONIMMIGRANTS UNDER THE IMMIGRATION AND NATIONALITY ACT, AS AMENDED Business and Media Visas § 41.53 Temporary workers and trainees... alien is eligible to receive a nonimmigrant visa. (c) Validity of visa. The period of validity of a visa...

  11. 22 CFR 41.53 - Temporary workers and trainees.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 41.53 Foreign Relations DEPARTMENT OF STATE VISAS VISAS: DOCUMENTATION OF NONIMMIGRANTS UNDER THE IMMIGRATION AND NATIONALITY ACT, AS AMENDED Business and Media Visas § 41.53 Temporary workers and trainees... alien is eligible to receive a nonimmigrant visa. (c) Validity of visa. The period of validity of a visa...

  12. 22 CFR 41.53 - Temporary workers and trainees.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 41.53 Foreign Relations DEPARTMENT OF STATE VISAS VISAS: DOCUMENTATION OF NONIMMIGRANTS UNDER THE IMMIGRATION AND NATIONALITY ACT, AS AMENDED Business and Media Visas § 41.53 Temporary workers and trainees... alien is eligible to receive a nonimmigrant visa. (c) Validity of visa. The period of validity of a visa...

  13. 78 FR 16411 - Drawbridge Operation Regulations; Saugatuck River, Westport, CT

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-15

    ... Regulations; Saugatuck River, Westport, CT AGENCY: Coast Guard, DHS. ACTION: Notice of temporary deviation from regulation. SUMMARY: The United States Coast Guard has issued a temporary deviation from the regulation governing the operation of the Route 136 Bridge across the Saugatuck River, mile 1.3, at Westport...

  14. Metal bacteriochlorins which act as dual singlet oxygen and superoxide generators.

    PubMed

    Fukuzumi, Shunichi; Ohkubo, Kei; Zheng, Xiang; Chen, Yihui; Pandey, Ravindra K; Zhan, Riqiang; Kadish, Karl M

    2008-03-06

    A series of stable free-base, Zn(II) and Pd(II) bacteriochlorins containing a fused six- or five-member diketo- or imide ring have been synthesized as good candidates for photodynamic therapy sensitizers, and their electrochemical, photophysical, and photochemical properties were examined. Photoexcitation of the palladium bacteriochlorin affords the triplet excited state without fluorescence emission, resulting in formation of singlet oxygen with a high quantum yield due to the heavy atom effect of palladium. Electrochemical studies revealed that the zinc bacteriochlorin has the smallest HOMO-LUMO gap of the investigated compounds, and this value is significantly lower than the triplet excited-state energy of the compound in benzonitrile. Such a small HOMO-LUMO gap of the zinc bacteriochlorin enables intermolecular photoinduced electron transfer from the triplet excited state to the ground state to produce both the radical cation and the radical anion. The radical anion thus produced can transfer an electron to molecular oxygen to produce superoxide anion which was detected by electron spin resonance. The same photosensitizer can also act as an efficient singlet oxygen generator. Thus, the same zinc bacteriochlorin can function as a sensitizer with a dual role in that it produces both singlet oxygen and superoxide anion in an aprotic solvent (benzonitrile).

  15. Unusual Passivation Ability of Superconcentrated Electrolytes toward Hard Carbon Negative Electrodes in Sodium-Ion Batteries.

    PubMed

    Takada, Koji; Yamada, Yuki; Watanabe, Eriko; Wang, Jianhui; Sodeyama, Keitaro; Tateyama, Yoshitaka; Hirata, Kazuhisa; Kawase, Takeo; Yamada, Atsuo

    2017-10-04

    The passivation of negative electrodes is key to achieving prolonged charge-discharge cycling with Na-ion batteries. Here, we report the unusual passivation ability of superconcentrated Na-salt electrolytes. For example, a 50 mol % sodium bis(fluorosulfonyl)amide (NaFSA)/succinonitrile (SN) electrolyte enables highly reversible Na + insertion into a hard carbon negative electrode without any electrolyte additive, functional binder, or electrode pretreatment. Importantly, an anion-derived passivation film is formed via preferential reduction of the anion upon charging, which can effectively suppress further electrolyte reduction. As a structural characteristic of the electrolyte, most anions are coordinated to multiple Na + cations at high concentration, which shifts the lowest unoccupied molecular orbitals of the anions downward, resulting in preferential anion reduction. The present work provides a new understanding of the passivation mechanism with respect to the coordination state of the anion.

  16. Vibrationally-resolved Photoelectron Spectroscopy of the Model GFP Chromophore Anion Revealing the Photoexcited S-1 State being both Vertically and Adiabatically Bound against the Photodetached D-0 Continuum

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Deng, Shihu; Kong, Xiangyu; Zhang, GuanXin

    2014-06-19

    The first excited state of the model green fluorescence protein (GFP) chromophore anion (S1) and its energy level against the electron-detached neutral radical, D0 state are crucial in determining the photophysics and the photo-induced dynamics of GFP. Extensive experimental and theoretical studies, particularly several very recent gas phase investigations concluded that S1 is a bound state in the Franck-Condon vertical region with respect to D0. However, what remains unknown and challenging is if S1 is bound adiabatically, primarily due to lack of accurate experimental measurements, as well as due to close proximity in energy for these two states that evenmore » sophisticated high-level ab initio calculations can’t reliably predict. Here, we report a negative ion photoelectron spectroscopy study on the model GFP chromophore anion, the deprotonated p-hydroxybenzylidene-2,3-dimethylimidazolinone anion (HBDI–). Despite the considerable size and low symmetry of the molecule, well resolved vibrational structures were obtained with the 0–0 transition being the most intense peak. The adiabatic (ADE) and vertical detachment energy (VDE) therefore are determined, both to be 2.73 ± 0.01 eV, indicating the detached D0 state is 0.16 eV higher in energy than the photon excited S1 state. The accurate ADE and VDE values and the well-resolved photoelectron spectra reported here provide much needed, robust benchmarks for future theoretical investigations.« less

  17. Photoelectron Spectroscopy and Density Functional Theory Studies of Iron Sulfur (FeS)m- (m = 2-8) Cluster Anions: Coexisting Multiple Spin States.

    PubMed

    Yin, Shi; Bernstein, Elliot R

    2017-10-05

    Iron sulfur cluster anions (FeS) m - (m = 2-8) are studied by photoelectron spectroscopy (PES) at 3.492 eV (355 nm) and 4.661 eV (266 nm) photon energies, and by density functional theory (DFT) calculations. The most probable structures and ground state spin multiplicities for (FeS) m - (m = 2-8) clusters are tentatively assigned through a comparison of their theoretical and experiment first vertical detachment energy (VDE) values. Many spin states lie within 0.5 eV of the ground spin state for the larger (FeS) m - (m ≥ 4) clusters. Theoretical VDEs of these low lying spin states are in good agreement with the experimental VDE values. Therefore, multiple spin states of each of these iron sulfur cluster anions probably coexist under the current experimental conditions. Such available multiple spin states must be considered when evaluating the properties and behavior of these iron sulfur clusters in real chemical and biological systems. The experimental first VDEs of (FeS) m - (m = 1-8) clusters are observed to change with the cluster size (number m). The first VDE trends noted can be related to the different properties of the highest singly occupied molecular orbitals (NBO, HSOMOs) of each cluster anion. The changing nature of the NBO/HSOMO of these (FeS) m - (m = 1-8) clusters from a p orbital on S, to a d orbital on Fe, and to an Fe-Fe bonding orbital is probably responsible for the observed increasing trend for their first VDEs with respect to m.

  18. Source Attribution of Cyanides Using Anionic Impurity Profiling, Stable Isotope Ratios, Trace Elemental Analysis and Chemometrics.

    PubMed

    Mirjankar, Nikhil S; Fraga, Carlos G; Carman, April J; Moran, James J

    2016-02-02

    Chemical attribution signatures (CAS) for chemical threat agents (CTAs), such as cyanides, are being investigated to provide an evidentiary link between CTAs and specific sources to support criminal investigations and prosecutions. Herein, stocks of KCN and NaCN were analyzed for trace anions by high performance ion chromatography (HPIC), carbon stable isotope ratio (δ(13)C) by isotope ratio mass spectrometry (IRMS), and trace elements by inductively coupled plasma optical emission spectroscopy (ICP-OES). The collected analytical data were evaluated using hierarchical cluster analysis (HCA), Fisher-ratio (F-ratio), interval partial least-squares (iPLS), genetic algorithm-based partial least-squares (GAPLS), partial least-squares discriminant analysis (PLSDA), K nearest neighbors (KNN), and support vector machines discriminant analysis (SVMDA). HCA of anion impurity profiles from multiple cyanide stocks from six reported countries of origin resulted in cyanide samples clustering into three groups, independent of the associated alkali metal (K or Na). The three groups were independently corroborated by HCA of cyanide elemental profiles and corresponded to countries each having one known solid cyanide factory: Czech Republic, Germany, and United States. Carbon stable isotope measurements resulted in two clusters: Germany and United States (the single Czech stock grouped with United States stocks). Classification errors for two validation studies using anion impurity profiles collected over five years on different instruments were as low as zero for KNN and SVMDA, demonstrating the excellent reliability associated with using anion impurities for matching a cyanide sample to its factory using our current cyanide stocks. Variable selection methods reduced errors for those classification methods having errors greater than zero; iPLS-forward selection and F-ratio typically provided the lowest errors. Finally, using anion profiles to classify cyanides to a specific stock or stock group for a subset of United States stocks resulted in cross-validation errors ranging from 0 to 5.3%.

  19. Mechanistic Significance of the Si–O–Pd Bond in the Palladium-Catalyzed Cross-Coupling Reactions of Arylsilanolates

    PubMed Central

    2016-01-01

    Through the combination of reaction kinetics (both stoichiometric and catalytic), solution- and solid-state characterization of arylpalladium(II) arylsilanolates, and computational analysis, the intermediacy of covalent adducts containing Si–O–Pd linkages in the cross-coupling reactions of arylsilanolates has been unambiguously established. Two mechanistically distinct pathways have been demonstrated: (1) transmetalation via a neutral 8-Si-4 intermediate that dominates in the absence of free silanolate (i.e., stoichiometric reactions of arylpalladium(II) arylsilanolate complexes), and (2) transmetalation via an anionic 10-Si-5 intermediate that dominates in the cross-coupling under catalytic conditions (i.e., in the presence of free silanolate). Arylpalladium(II) arylsilanolate complexes bearing various phosphine ligands have been isolated, fully characterized, and evaluated for their kinetic competence under thermal (stoichiometric) and anionic (catalytic) conditions. Comparison of the rates for thermal and anionic activation suggested, but did not prove, that intermediates containing the Si–O–Pd linkage were involved in the cross-coupling process. The isolation of a coordinatively unsaturated, T-shaped arylpalladium(II) arylsilanolate complex ligated with t-Bu3P allowed the unambiguous demonstration of the operation of both pathways involving 8-Si-4 and 10-Si-5 intermediates. Three kinetic regimes were identified: (1) with 0.5–1.0 equiv of added silanolate (with respect to arylpalladium bromide), thermal transmetalation via a neutral 8-Si-4 intermediate; (2) with 1.0–5.0 equiv of added silanolate, activated transmetalation via an anionic 10-Si-5 intermediate; and (3) with >5.0 equiv of added silanolate, concentration-independent (saturation) activated transmetalation via an anionic 10-Si-5 intermediate. Transition states for the intramolecular transmetalation of neutral (8-Si-4) and anionic (10-Si-5) intermediates have been located computationally, and the anionic pathway is favored by 1.8 kcal/mol. The energies of all intermediates and transition states are highly dependent on the configuration around the palladium atom. PMID:25945516

  20. Ultrafast above-threshold dynamics of the radical anion of a prototypical quinone electron-acceptor.

    PubMed

    Horke, Daniel A; Li, Quansong; Blancafort, Lluís; Verlet, Jan R R

    2013-08-01

    Quinones feature prominently as electron acceptors in nature. Their electron-transfer reactions are often highly exergonic, for which Marcus theory predicts reduced electron-transfer rates because of a free-energy barrier that occurs in the inverted region. However, the electron-transfer kinetics that involve quinones can appear barrierless. Here, we consider the intrinsic properties of the para-benzoquinone radical anion, which serves as the prototypical electron-transfer reaction product involving a quinone-based acceptor. Using time-resolved photoelectron spectroscopy and ab initio calculations, we show that excitation at 400 and 480 nm yields excited states that are unbound with respect to electron loss. These excited states are shown to decay on a sub-40 fs timescale through a series of conical intersections with lower-lying excited states, ultimately to form the ground anionic state and avoid autodetachment. From an isolated electron-acceptor perspective, this ultrafast stabilization mechanism accounts for the ability of para-benzoquinone to capture and retain electrons.

  1. Admission-Group Salary Differentials in the United States: The Significance of Labor Market Institutional Selection of High-Skilled Workers*

    PubMed Central

    Hao, Lingxin

    2015-01-01

    In 1990 a temporary-to-permanent pathway was established for highly skilled workers admitted to the United States under nonimmigrant programs. The paper argues that this policy shift has allowed employers to play a crucial role in the immigration of highly skilled workers, thereby creating labor-market institutional selection that gives a salary advantage to highly skilled temporary-admitted workers retained in the United States. Through analyses of the salary differentials among admission-category groups, the paper finds that the salary advantage is based on recruitment from Western countries, adjustment from temporary to permanent status after a second employer screening, working in the information technology sector and the private sector, holding a supervisory position, or having a skill-matched job, all of which are consequences of institutional selection rather than individual self-selection. Our results also reveal a difference between those admitted from abroad and those recruited from graduating foreign students in USA higher educational institutions, which suggests a distinction between overseas hiring and domestic hiring. Policy implications for the United States and other receiving countries are discussed. PMID:26269690

  2. Phase-Change Thermoplastic Elastomer Blends for Tunable Shape Memory by Physical Design

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mineart, Kenneth P.; Tallury, Syamal S.; Li, Tao

    Shape-memory polymers (SMPs) change shape upon exposure to an environmental stimulus.1-3 They are of considerable importance in the ongoing development of stimuli-responsive biomedical4,5 and deployable6 devices, and their function depends on the presence of two components.7 The first provides mechanical rigidity to ensure retention of one or more temporary strain states and also serves as a switch capable of releasing a temporary strain state. The second, a network-forming component, is required to restore the polymer to a prior strain state upon stimulation. In thermally-activated SMPs, the switching element typically relies on a melting or glass transition temperature,1-3,7 and broad ormore » multiple switches permit several temporary strain states.8-10 Chemical integration of network-forming and switching species endows SMPs with specific properties.8,10,11 Here, we demonstrate that phase-change materials incorporated into network-forming macromolecules yield shape-memory polymer blends (SMPBs) with physically tunable switching temperatures and recovery kinetics for use in multi-responsive laminates and shape-change electronics.« less

  3. Coupled-cluster and explicitly correlated perturbation-theory calculations of the uracil anion.

    PubMed

    Bachorz, Rafał A; Klopper, Wim; Gutowski, Maciej

    2007-02-28

    A valence-type anion of the canonical tautomer of uracil has been characterized using explicitly correlated second-order Moller-Plesset perturbation theory (RI-MP2-R12) in conjunction with conventional coupled-cluster theory with single, double, and perturbative triple excitations. At this level of electron-correlation treatment and after inclusion of a zero-point vibrational energy correction, determined in the harmonic approximation at the RI-MP2 level of theory, the valence anion is adiabatically stable with respect to the neutral molecule by 40 meV. The anion is characterized by a vertical detachment energy of 0.60 eV. To obtain accurate estimates of the vertical and adiabatic electron binding energies, a scheme was applied in which electronic energy contributions from various levels of theory were added, each of them extrapolated to the corresponding basis-set limit. The MP2 basis-set limits were also evaluated using an explicitly correlated approach, and the results of these calculations are in agreement with the extrapolated values. A remarkable feature of the valence anionic state is that the adiabatic electron binding energy is positive but smaller than the adiabatic electron binding energy of the dipole-bound state.

  4. Estimation of temporary emigration in male toads

    USGS Publications Warehouse

    Muths, E.; Scherer, R. D.; Corn, P.S.; Lambert, B.A.

    2006-01-01

    Male boreal toads (Bufo boreas) are thought to return to the breeding site every year but, if absent in a particular year, will be more likely to return the following year. Using Pollock's robust design we estimated temporary emigration (the probability a male toad is absent from a breeding site in a given year) at three locations in Colorado, USA: two in Rocky Mountain National Park and one in Chaffee County. We present data that suggest that not all male toads return to the breeding site every year. Our analyses indicate that temporary emigration varies by site and time (for example, from 1992 to 1998, the probability of temporary emigration ranged from 10% to 29% and from 3% to 95% at Lost Lake and Kettle Tarn, respectively). Although the results provide weak evidence that males are more likely to return after a year's hiatus, a general pattern of state-dependent temporary emigration was not supported. We also hypothesized relationships between temporary emigration and a number of weather variables. While some competitive models included weather covariates, imprecise and variable estimates of the effects of these covariates precluded fully defining their impact on temporary emigration. ?? 2006 by the Ecological Society of America.

  5. 76 FR 3451 - Wage Methodology for the Temporary Non-agricultural Employment H-2B Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-19

    ...The Department of Labor (the Department or DOL) is amending its regulations governing the certification for the employment of nonimmigrant workers in temporary or seasonal non-agricultural employment. This Final Rule revises the methodology by which the Department calculates the prevailing wages to be paid to H-2B workers and United States (U.S.) workers recruited in connection with a temporary labor certification for use in petitioning the Department of Homeland Security (DHS) to employ a nonimmigrant worker in H-2B status.

  6. Fluoride anion sensing mechanism of 2-ureido-4[1H]-pyrimidinone quadruple hydrogen-bonded supramolecular assembly: photoinduced electron transfer and partial configuration change.

    PubMed

    Chen, Jun-Sheng; Zhou, Pan-Wang; Li, Guang-Yue; Chu, Tian-Shu; He, Guo-Zhong

    2013-05-02

    The fluoride anion sensing mechanism of 6-methyl-5-(9-methylene-anthracene)-(2-butylureido-4[1H]-pyrimidinone) (AnUP) has been investigated using the DFT/TDDFT method. The theoretical results indicate that the proton of the N3-H3 group in pyrimidine moiety is captured by the added fluoride anion and then deprotonated. The calculated vertical excitation energies of AnUP-dimer and its deprotonated form agree well with the experimental results. The molecular orbital analysis demonstrates that the first excited state (S1) of AnUP-dimer is a local excited state with a π-π* transition, whereas for the deprotonated form, S1 is a completely charge-separation state and is responsible for the photoinduced electron transfer (PET) process. The PET process from anthracene to the pyrimidine moiety leads to the fluorescence quenching.

  7. 78 FR 1259 - Labor Certification Process for the Temporary Employment of Aliens in Agriculture in the United...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-08

    ... DEPARTMENT OF LABOR Employment and Training Administration Labor Certification Process for the Temporary Employment of Aliens in Agriculture in the United States: 2013 Adverse Effect Wage Rates AGENCY... Department of Agriculture (USDA). 20 CFR 655.120(c) requires that the Administrator of the Office of Foreign...

  8. 76 FR 79711 - Labor Certification Process for the Temporary Employment of Aliens in Agriculture in the United...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-22

    ... DEPARTMENT OF LABOR Employment and Training Administration Labor Certification Process for the Temporary Employment of Aliens in Agriculture in the United States: 2012 Adverse Effect Wage Rates AGENCY... Department of Agriculture (USDA). 20 CFR 655.120(c) requires the Administrator of the Office of Foreign Labor...

  9. 77 FR 60430 - Brigham Oil & Gas, L.P.; Notice for Temporary Waiver of Filing and Reporting Requirements

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-03

    ... (2012), Brigham Oil & Gas, L.P., (Brigham Oil & Gas) requested that the Commission grant a temporary... requirements applicable to interstate common carrier pipelines. Brigham Oil & Gas requested review on an..., 2012. Brigham Oil & Gas stated that they are developing three crude oil gathering systems in North...

  10. 76 FR 68657 - Fisheries of the Northeastern United States; Atlantic Herring Fishery; Temporary Removal of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-07

    ...; Temporary Removal of Herring Trip Limit in Atlantic Herring Management Area 3 AGENCY: National Marine... limit for the Atlantic herring fishery in Management Area 3 because recent catch data indicate that 95...-kg), consistent with their Atlantic herring permit category, effective 0001 hr, November 7, 2011...

  11. 18 CFR 157.17 - Applications for temporary certificates in cases of emergency.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Applications for temporary certificates in cases of emergency. 157.17 Section 157.17 Conservation of Power and Water... responsible officer of applicant having knowledge of the facts, and must state clearly and specifically the...

  12. 19 CFR 210.43 - Petitions for review of initial determinations on matters other than temporary relief.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... matters other than temporary relief. 210.43 Section 210.43 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT..., the Federal Trade Commission, the U.S. Customs Service, and such other departments and agencies as the...

  13. 76 FR 23485 - Safety Zone; Red River

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-27

    ...-AA00 Safety Zone; Red River AGENCY: Coast Guard, DHS. ACTION: Temporary final rule. SUMMARY: The Coast Guard is establishing a temporary safety zone for all waters of the Red River in the State of North..., extending the entire width of the river. This safety zone is needed to protect persons and vessels from...

  14. 20 CFR 655.101 - Authority of the Office of Foreign Labor Certification (OFLC) Administrator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Authority of the Office of Foreign Labor Certification (OFLC) Administrator. 655.101 Section 655.101 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR TEMPORARY EMPLOYMENT OF FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process for Temporary...

  15. Real-time monitoring of ischemia inside stomach.

    PubMed

    Tahirbegi, Islam Bogachan; Mir, Mònica; Samitier, Josep

    2013-02-15

    The low pH in the gastric juice of the stomach makes it difficult to fabricate stable and functional all-solid-state pH ISE sensors to sense ischemia, mainly because of anion interference and adhesion problem between the ISE membrane and the electrode surface. In this work, the adhesion of ISE membrane on solid surface at low pH was improved by modifying the surface with a conductive substrate containing hydrophilic and hydrophobic groups. This creates a stable and robust candidate for low pH applications. Moreover, anion interference problem at low pH was solved by integration of all-solid-state ISE and internal reference electrodes on an array. So, the same tendencies of anion interferences for all-solid-state ISE and all-solid-state reference electrodes cancel each other in differential potentiometric detection. The developed sensor presents a novel all-solid-state potentiometric, miniaturized and mass producible pH ISE sensor for detecting ischemia on the stomach tissue on an array designed for endoscopic applications. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. Competition between photodetachment and autodetachment of the 2{sup 1}ππ{sup *} state of the green fluorescent protein chromophore anion

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mooney, Ciarán R. S.; Parkes, Michael A.; Zhang, Lijuan

    2014-05-28

    Using a combination of photoelectron spectroscopy measurements and quantum chemistry calculations, we have identified competing electron emission processes that contribute to the 350–315 nm photoelectron spectra of the deprotonated green fluorescent protein chromophore anion, p-hydroxybenzylidene-2,3-dimethylimidazolinone. As well as direct electron detachment from S{sub 0}, we observe resonant excitation of the 2{sup 1}ππ* state of the anion followed by autodetachment. The experimental photoelectron spectra are found to be significantly broader than photoelectron spectrum calculated using the Franck-Condon method and we attribute this to rapid (∼10 fs) vibrational decoherence, or intramolecular vibrational energy redistribution, within the neutral radical.

  17. Large Fluorescence Response by Alcohol from a Bis(benzoxazole)-Zinc(II) Complex: The Role of Excited State Intramolecular Proton Transfer

    PubMed Central

    Wang, Junfeng; Chu, Qinghui; Liu, Xiumin; Wesdemiotis, Chrys

    2013-01-01

    The formation of a bis(HBO) anion is known to turn-on the fluorescence to give red emission, via controlling the excited-state intramolecular proton transfer (ESIPT). The poor stability of the formed anion, however, hampered its application. The anion stability is found to be greatly improved by attaching the anion to Zn2+ cation (i.e. forming zinc complex), whose emission is at λem ≈ 550 and 760 nm. Interestingly, addition of methanol to the zinc complex induces a remarkable red fluorescence (λem ≈ 630 nm, ϕfl ≈ 0.8). With the aid of spectroscopic studies (1H NMR, UV-vis, fluorescence, and mass spectra), the structures of the zinc complexes are characterized. The emission species is identified as a dimer-like structure. The study thus reveals an effective fluorescence switching mechanism that could further advance the application of ESIPT-based sensors. PMID:23514312

  18. Supramolecular architectures with π-acidic 3,6-bis(2-pyridyl)-1,2,4,5-tetrazine cavities: role of anion-π interactions in the remarkable stability of Fe(II) metallacycles in solution.

    PubMed

    Chifotides, Helen T; Giles, Ian D; Dunbar, Kim R

    2013-02-27

    The comprehensive investigation reported herein provides compelling evidence that anion-π interactions are the main driving force in the formation of self-assembled Fe(II)-templated metallacycles with bptz [3,6-bis(2-pyridyl)-1,2,4,5-tetrazine] in high yields. It was demonstrated by X-ray crystallography, (1)H NMR, solution and solid-state MAS (19)F NMR spectroscopies, CV and MS studies that the anions [X](-) = [BF(4)](-), [ClO(4)](-) and the anions [Y](-) = [SbF(6)](-), [AsF(6)](-), [PF(6)](-) template molecular squares [Fe(4)(bptz)(4)(CH(3)CN)(8)][X](8) and pentagons [Fe(5)(bptz)(5)(CH(3)CN)(10)][Y](10), respectively. The X-ray structures of [{Fe(4)(bptz)(4)(CH(3)CN)(8)}⊂BF(4)][BF(4)](7) and [{Fe(5)(bptz)(5)(CH(3)CN)(10)}⊂2SbF(6)][SbF(6)](8) revealed that the [BF(4)](-) and [SbF(6)](-) anions occupy the π-acidic cavities, establishing close directional F···C(tetrazine) contacts with the tetrazine rings that are by ~0.4 Å shorter than the sum of the F···C van der Waals radii (ΣR(vdW) F···C = 3.17 Å). The number and strength of F···C(tetrazine) contacts are maximized; the F···C(tetrazine) distances and anion positioning versus the polygon opposing tetrazine rings are in agreement with DFT calculations for C(2)N(4)R(2)···[X](-)···C(2)N(4)R(2) (R = F, CN; [X](-) = [BF(4)](-), [PF(6)](-)). In unprecedented solid-state (19)F MAS NMR studies, the templating anions, engaged in anion-π interactions in the solid state, exhibit downfield chemical shifts Δδ((19)F) ≈ 3.5-4.0 ppm versus peripheral anions. NMR, CV, and MS studies also establish that the Fe(II) metallacycles remain intact in solution. Additionally, interconversion studies between the Fe(II) metallacycles in solution, monitored by (1)H NMR spectroscopy, underscore the remarkable stability of the metallapentacycles [Fe(5)(bptz)(5)(CH(3)CN)(10)][PF(6)](10) ≪ [Fe(5)(bptz)(5)(CH(3)CN)(10)][SbF(6)](10) < [Fe(5)(bptz)(5)(CH(3)CN)(10)][AsF(6)](10) versus [Fe(4)(bptz)(4)(CH(3)CN)(8)][BF(4)](8), given the inherent angle strain in five-membered rings. Finally, the low anion activation energies of encapsulation (ΔG(‡) ≈ 50 kJ/mol), determined from variable-temperature (19)F NMR studies for [Fe(5)(bptz)(5)(CH(3)CN)(10)][PF(6)](10) and [Zn(4)(bptz)(4)(CH(3)CN)(8)][BF(4)](8), confirm anion encapsulation in the π-acidic cavities by anion-π contacts (~20-70 kJ/mol).

  19. CATALYTIC PROMOTION OF THE ADSORPTION OF VANADIUM ON AN ANIONIC EXCHANGE RESIN

    DOEpatents

    Bailes, R.H.; Ellis, D.A.

    1958-08-26

    An improvement in the process for the recovery of vanadium from acidic phosphatic solutions is presented. In this process the vanadium is first oxidized to the pentavaleat state, and is then separated by contacting such solutions with an anion exchange resin whereby adsorption of the complexed pentavalent vanadium is effected. The improvement lies in the fact that adsorp tion of the vanadium complex by the anion exchange resin is promoted and improved by providing fiuoride ions in solution to be contacted.

  20. Aromatic thiol-mediated cleavage of N-O bonds enables chemical ubiquitylation of folded proteins

    NASA Astrophysics Data System (ADS)

    Weller, Caroline E.; Dhall, Abhinav; Ding, Feizhi; Linares, Edlaine; Whedon, Samuel D.; Senger, Nicholas A.; Tyson, Elizabeth L.; Bagert, John D.; Li, Xiaosong; Augusto, Ohara; Chatterjee, Champak

    2016-09-01

    Access to protein substrates homogenously modified by ubiquitin (Ub) is critical for biophysical and biochemical investigations aimed at deconvoluting the myriad biological roles for Ub. Current chemical strategies for protein ubiquitylation, however, employ temporary ligation auxiliaries that are removed under harsh denaturing conditions and have limited applicability. We report an unprecedented aromatic thiol-mediated N-O bond cleavage and its application towards native chemical ubiquitylation with the ligation auxiliary 2-aminooxyethanethiol. Our interrogation of the reaction mechanism suggests a disulfide radical anion as the active species capable of cleaving the N-O bond. The successful semisynthesis of full-length histone H2B modified by the small ubiquitin-like modifier-3 (SUMO-3) protein further demonstrates the generalizability and compatibility of our strategy with folded proteins.

  1. 76 FR 22033 - Safety Zone; Red River Safety Zone, Red River, MN

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-20

    ...-AAOO Safety Zone; Red River Safety Zone, Red River, MN AGENCY: Coast Guard, DHS. ACTION: Temporary... a temporary safety zone on the Red River, MN. This safety zone is being established to ensure the... Red River in the State of Minnesota north of a line drawn across latitude 46[deg]20'00'' N, including...

  2. 76 FR 18292 - Culturally Significant Objects Imported for Exhibition Determinations: “The Steins Collect...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-01

    ... the San Francisco Museum of Modern Art, San Francisco, CA, from on or about May 21, 2011, until on or about September 6, 2011, and the temporary display of six of the objects at The Metropolitan Museum of..., and the Parisian Avant-Garde'' imported from abroad for temporary exhibition within the United States...

  3. 77 FR 16157 - Changes to the Labor Certification Process for the Temporary Non-Agricultural Employment of H-2B...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-20

    ... DEPARTMENT OF LABOR Employment and Training Administration 20 CFR Part 655 RIN 1205-AB58 Changes to the Labor Certification Process for the Temporary Non- Agricultural Employment of H-2B Aliens in the United States; Transition Period AGENCY: Employment and Training Administration, Department of...

  4. 77 FR 24137 - Changes to the Labor Certification Process for the Temporary Non-Agricultural Employment of H-2B...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-23

    ... DEPARTMENT OF LABOR Employment and Training Administration 20 CFR Part 655 RIN 1205-AB58 Changes to the Labor Certification Process for the Temporary Non- Agricultural Employment of H-2B Aliens in the United States; Revisions to Transition Period AGENCY: Employment and Training Administration...

  5. Managing Labor Market Changes: Essential Skills for Entrepreneurs and Intrapreneurs

    ERIC Educational Resources Information Center

    O'Neill, Barbara

    2014-01-01

    The United States labor market has undergone a dramatic sea change with increasing numbers of permanent freelancers and temporary workers. One in three workers has a temporary freelance job. It is estimated that, by 2020, more than 40% of the American labor force-60 million people-will be self-employed. This article discusses labor force trends,…

  6. 26 CFR 1.103(n)-6T - Determinations of population (temporary).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...(n)-6T Section 1.103(n)-6T Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY....103(n)-6T Determinations of population (temporary). Q-1: What is the proper method for determining...(n)-6T: Example. County Q is located within State R. There are no constitutional home rule cities in...

  7. Korean Temporary Migrant Mothers' Conceptualization of Parent Involvement in the United States

    ERIC Educational Resources Information Center

    Chung, Hoewook

    2013-01-01

    The purpose of this study is to gain insight into how Korean temporary migrant mothers conceptualize the nature of parent involvement in the USA. The participants in this study consisted of Korean mothers who were educated in Korea, migrated temporarily to the USA for educational purposes, and sent their children to American schools. Using the…

  8. 75 FR 69903 - Fisheries of the Northeastern United States; Atlantic Herring Fishery; Temporary Removal of 2,000...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-16

    ...; Temporary Removal of 2,000-lb (907.2 kg) Herring Trip Limit in Atlantic Herring Management Area 1A AGENCY... for the Atlantic herring fishery in Management Area 1A (Area 1A). The trip limit removal is because... CONTACT: Lindsey Feldman, Fishery Management Specialist, 978-675-2179. SUPPLEMENTARY INFORMATION...

  9. 77 FR 10960 - Security Zone, East River and Bronx Kill; Randalls and Wards Islands, NY

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-24

    ...-AA87 Security Zone, East River and Bronx Kill; Randalls and Wards Islands, NY AGENCY: Coast Guard, DHS. ACTION: Temporary final rule. SUMMARY: The Coast Guard is establishing a temporary security zone on the... security zone is necessary to ensure the safety of the President of the United States, members of his...

  10. 75 FR 52972 - Notice of Temporary Closures and Restrictions on Specific Uses of Public Lands in Pershing County...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-30

    ..., more or less. The closure and temporary restrictions are necessary to provide a safe environment for... or activities that are necessary to provide a safe environment for the public and for participants in... and protect the environment on public lands, as well as support state and local law enforcement...

  11. 26 CFR 1.909-6T - Pre-2011 foreign tax credit splitting events (temporary).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 10 2013-04-01 2013-04-01 false Pre-2011 foreign tax credit splitting events... States § 1.909-6T Pre-2011 foreign tax credit splitting events (temporary). (a) Foreign tax credit splitting event—(1) In general. This section provides rules for determining whether foreign income taxes...

  12. A photoelectron imaging and quantum chemistry study of the deprotonated indole anion.

    PubMed

    Parkes, Michael A; Crellin, Jonathan; Henley, Alice; Fielding, Helen H

    2018-05-29

    Indole is an important molecular motif in many biological molecules and exists in its deprotonated anionic form in the cyan fluorescent protein, an analogue of green fluorescent protein. However, the electronic structure of the deprotonated indole anion has been relatively unexplored. Here, we use a combination of anion photoelectron velocity-map imaging measurements and quantum chemistry calculations to probe the electronic structure of the deprotonated indole anion. We report vertical detachment energies (VDEs) of 2.45 ± 0.05 eV and 3.20 ± 0.05 eV, respectively. The value for D0 is in agreement with recent high-resolution measurements whereas the value for D1 is a new measurement. We find that the first electronically excited singlet state of the anion, S1(ππ*), lies above the VDE and has shape resonance character with respect to the D0 detachment continuum and Feshbach resonance character with respect to the D1 continuum.

  13. Proton transfer from water to ketyl radical anion: Assessment of critical size of hydrated cluster and free energy barrier in solution from first principles simulations

    NASA Astrophysics Data System (ADS)

    Biswas, Sohag; Dasgupta, Teesta; Mallik, Bhabani S.

    2016-09-01

    We present the reactivity of an organic intermediate by studying the proton transfer process from water to ketyl radical anion using gas phase electronic structure calculations and the metadynamics method based first principles molecular dynamics (FPMD) simulations. Our results indicate that during the micro solvation of anion by water molecules systematically, the presence of minimum three water molecules in the gas phase cluster is sufficient to observe the proton transfer event. The analysis of trajectories obtained from initial FPMD simulation of an aqueous solution of the anion does not show any evident of complete transfer of the proton from water. The cooperativity of water molecules and the relatively weak anion-water interaction in liquid state prohibit the full release of the proton. Using biasing potential through first principles metadynamics simulations, we report the observation of proton transfer reaction from water to ketyl radical anion with a barrier height of 16.0 kJ/mol.

  14. Photoelectron Spectroscopy of the Doubly-Charged Anions [MIVO(mnt)2]2- (M=Mo, W; mnt=S2C2(CN)22-): Access to the Ground and Excited States of the [MvO(mnt)2]-Anion

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Waters, Tom; Wang, Xue B.; Yang, Xin

    2004-04-21

    Photodetachment photoelectron spectroscopy was used to investigate the electronic structure of the doubly charged complexes [MIVO(mnt)2]2- (M=Mo, W;mnt=1,2 dicyanoethenedithiolato). These dianions are stable in the gas phase and are minimal models for the active sites of the dimethyl sulfoxide reductase family of molybdenum enzymes and of related tungsten enzymes. Adiabatic and vertical electron binding energies for both species were measured, providing detailed information about molecular orbital energy levels of the parent dianions as well as the ground and excited states of the product anions [MvO(mnt)2]. Density functional theory calculations were used to assist assignment of the detachment features.

  15. Pyromellitamide aggregates and their response to anion stimuli.

    PubMed

    Webb, James E A; Crossley, Maxwell J; Turner, Peter; Thordarson, Pall

    2007-06-06

    The N,N',N'',N'''-1,2,4,5-tetra(ethylhexanoate) pyromellitamide is found to be capable of both intermolecular aggregation and binding to small anions. It is synthesized by aminolysis of pyromellitic anhydride with ethanolamine, followed by a reaction with hexanoyl chloride. The single-crystal X-ray structure of the pyromellitamide shows that it forms one-dimensional columnar stacks through an intermolecular hydrogen-bonding network. It also forms self-assembled gels in nonpolar solvents, presumably by a hydrogen-bonding network similar to the solid-state structure as shown by IR and XRD studies. Aggregation by intermolecular hydrogen bonding of the pyromellitamide is also observed by NMR and IR in solution. Fitting of NMR dilution data for pyromellitamide in d6-acetone to a cooperative aggregation model gave KE=232 M-1 and positive cooperativity of aggregation (rho=0.22). The pyromellitamide binds to a range of small anions with the binding strength decreasing in the order chloride>acetate>bromide>nitrate approximately iodide. The data indicate that the pyromellitamide binds two anions and that it displays negative cooperativity. The intermolecular aggregation of the pyromellitamide can also be altered using small anion stimuli; anion addition to preformed self-assembled pyromellitamide gels causes their collapse. The kinetics of anion-induced gel collapse are qualitatively correlated to the binding affinities of the same anions in solution. The cooperative anion binding properties and the sensitivity of the self-assembled gels formed by pyromellitamide toward anions could be useful in the development of sensors and switching/releasing devices.

  16. Review on anionic redox for high-capacity lithium- and sodium-ion batteries

    NASA Astrophysics Data System (ADS)

    Zhao, Chenglong; Wang, Qidi; Lu, Yaxiang; Hu, Yong-Sheng; Li, Baohua; Chen, Liquan

    2017-05-01

    Rechargeable batteries, especially lithium-ion batteries, are now widely used as power sources for portable electronics and electric vehicles, but material innovations are still needed to satisfy the increasing demand for larger energy density. Recently, lithium- and sodium-rich electrode materials, including the A2MO3-family layered compounds (A  =  Li, Na; M  =  Mn4+, Ru4+, etc), have been extensively studied as potential high-capacity electrode materials for a cumulative cationic and anionic redox activity. Negatively charged oxide ions can potentially donate electrons to compensate for the absence of oxidable transition metals as a redox center to further increase the reversible capacity. Understanding and controlling the state-of-the-art anionic redox processes is pivotal for the design of advanced energy materials, highlighted in rechargeable batteries. Hence, experimental and theoretical approaches have been developed to consecutively study the diverting processes, states, and structures involved. In this review, we attempt to present a literature overview and provide insight into the reaction mechanism with respect to the anionic redox processes, proposing some opinions as target oriented. It is hoped that, through this discussion, the search for anionic redox electrode materials with high-capacity rechargeable batteries can be advanced, and practical applications realized as soon as possible.

  17. 26 CFR 1.904(g)-0T - Outline of regulation provisions (temporary).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ....904(g)-0T Section 1.904(g)-0T Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Income from Sources Without the United States § 1.904(g)-0T Outline of regulation provisions (temporary). This section lists the headings for §§ 1.904(g)-1T through 1...

  18. 75 FR 72734 - Fisheries of the Northeastern United States; Atlantic Herring Fishery; Temporary Removal of 2,000...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-26

    ...; Temporary Removal of 2,000-lb (907.2-kg) Herring Trip Limit in Atlantic Herring Management Area 1A AGENCY... for the Atlantic herring fishery in Management Area 1A (Area 1A) because catch data indicate that 95..., Fishery Management Specialist, 978-675-2179. SUPPLEMENTARY INFORMATION: Regulations governing the Atlantic...

  19. 19 CFR 210.44 - Commission review on its own motion of initial determinations on matters other than temporary...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Determinations and Actions Taken § 210.44 Commission review on its own motion of initial determinations on... 19 Customs Duties 3 2010-04-01 2010-04-01 false Commission review on its own motion of initial determinations on matters other than temporary relief. 210.44 Section 210.44 Customs Duties UNITED STATES...

  20. Analysis of Labor Market Adjustments in the Clerical Temporary Help Market: 1953-1960.

    ERIC Educational Resources Information Center

    1971

    This report is a theoretical and empirical study of the clerical temporary help labor market with particular reference to how that market was affected by changing states of the permanent labor market. Special attention is paid to the hiring process and to the determination of worker quality over the business cycle. Data for the study were obtained…

  1. Terahertz-visible two-photon rotational spectroscopy of cold OD-

    NASA Astrophysics Data System (ADS)

    Lee, Seunghyun; Hauser, Daniel; Lakhmanskaya, Olga; Spieler, Steffen; Endres, Eric S.; Geistlinger, Katharina; Kumar, Sunil S.; Wester, Roland

    2016-03-01

    We present a method to measure rotational transitions of molecular anions in the terahertz domain by sequential two-photon absorption. Ion excitation by bound-bound terahertz absorption is probed by absorption in the visible on a bound-free transition. The visible frequency is tuned to a state-selective photodetachment transition of the excited anions. This provides a terahertz action spectrum for just a few hundred molecular ions. To demonstrate this we measure the two lowest rotational transitions, J =1 ←0 and J =2 ←1 of OD- anions in a cryogenic 22-pole trap. We obtain rotational transition frequencies of 598 596.08(19) MHz for J =1 ←0 and 1 196 791.57(27) MHz for J =2 ←1 of OD-, in good agreement with their only previous measurement. This two-photon scheme opens up terahertz rovibrational spectroscopy for a range of molecular anions, in particular for polyatomic and cluster anions.

  2. Combining reactive sputtering and rapid thermal processing for synthesis and discovery of metal oxynitrides

    DOE PAGES

    Zhou, Lan; Suram, Santosh K.; Becerra-Stasiewicz, Natalie; ...

    2015-05-27

    Recent efforts have demonstrated enhanced tailoring of material functionality with mixed-anion materials, yet exploratory research with mixed-anion chemistries is limited by the sensitivity of these materials to synthesis conditions. In order to synthesize a particular metal oxynitride compound by traditional reactive annealing we require specific, limited ranges of both oxygen and nitrogen chemical potentials in order to establish equilibrium between the solid-state material and a reactive atmosphere. While using Ta-O-N as an example system, we describe a combination of reactive sputter deposition and rapid thermal processing for synthesis of mixed-anion inorganic materials. Heuristic optimization of reactive gas pressures to attainmore » a desired anion stoichiometry is discussed, and the ability of rapid thermal processing to enable amorphous to crystalline transitions without preferential anion loss is demonstrated through the controlled synthesis of nitride, oxide and oxynitride phases.« less

  3. Method of separating thorium from plutonium

    DOEpatents

    Clifton, David G.; Blum, Thomas W.

    1984-01-01

    A method of chemically separating plutonium from thorium. Plutonium and thorium to be separated are dissolved in an aqueous feed solution, preferably as the nitrate salts. The feed solution is acidified and sodium nitrite is added to the solution to adjust the valence of the plutonium to the +4 state. A chloride salt, preferably sodium chloride, is then added to the solution to induce formation of an anionic plutonium chloride complex. The anionic plutonium chloride complex and the thorium in solution are then separated by ion exchange on a strong base anion exchange column.

  4. Method of separating thorium from plutonium

    DOEpatents

    Clifton, D.G.; Blum, T.W.

    A method of chemically separating plutonium from thorium is claimed. Plutonium and thorium to be separated are dissolved in an aqueous feed solution, preferably as the nitrate salts. The feed solution is acidified and sodium nitrite is added to the solution to adjust the valence of the plutonium to the +4 state. A chloride salt, preferably sodium chloride, is then added to the solution to induce formation of an anionic plutonium chloride complex. The anionic plutonium chloride complex and the thorium in solution are then separated by ion exchange on a strong base anion exchange column.

  5. Method of separating thorium from plutonium

    DOEpatents

    Clifton, D.G.; Blum, T.W.

    1984-07-10

    A method is described for chemically separating plutonium from thorium. Plutonium and thorium to be separated are dissolved in an aqueous feed solution, preferably as the nitrate salts. The feed solution is acidified and sodium nitrite is added to the solution to adjust the valence of the plutonium to the +4 state. A chloride salt, preferably sodium chloride, is then added to the solution to induce formation of an anionic plutonium chloride complex. The anionic plutonium chloride complex and the thorium in solution are then separated by ion exchange on a strong base anion exchange column.

  6. NH2- in a cold ion trap with He buffer gas: Ab initio quantum modeling of the interaction potential and of state-changing multichannel dynamics

    NASA Astrophysics Data System (ADS)

    Hernández Vera, Mario; Yurtsever, Ersin; Wester, Roland; Gianturco, Franco A.

    2018-05-01

    We present an extensive range of accurate ab initio calculations, which map in detail the spatial electronic potential energy surface that describes the interaction between the molecular anion NH2 - (1A1) in its ground electronic state and the He atom. The time-independent close-coupling method is employed to generate the corresponding rotationally inelastic cross sections, and then the state-changing rates over a range of temperatures from 10 to 30 K, which is expected to realistically represent the experimental trapping conditions for this ion in a radio frequency ion trap filled with helium buffer gas. The overall evolutionary kinetics of the rotational level population involving the molecular anion in the cold trap is also modelled during a photodetachment experiment and analyzed using the computed rates. The present results clearly indicate the possibility of selectively detecting differences in behavior between the ortho- and para-anions undergoing photodetachment in the trap.

  7. Electronic and rovibrational quantum chemical analysis of C3P-: the next interstellar anion?

    NASA Astrophysics Data System (ADS)

    Fortenberry, Ryan C.; Lukemire, Joseph A.

    2015-11-01

    C3P- is analogous to the known interstellar anion C3N- with phosphorus replacing nitrogen in a simple step down the periodic table. In this work, it is shown that C3P- is likely to possess a dipole-bound excited state. It has been hypothesized and observationally supported that dipole-bound excited states are an avenue through which anions could be formed in the interstellar medium. Additionally, C3P- has a valence excited state that may lead to further stabilization of this molecule, and C3P- has a larger dipole moment than neutral C3P (˜6 D versus ˜4 D). As such, C3P- is probably a more detectable astromolecule than even its corresponding neutral radical. Highly accurate quantum chemical quartic force fields are also applied to C3P- and its singly 13C substituted isotopologues in order to provide structures, vibrational frequencies, and spectroscopic constants that may aid in its detection.

  8. Relaxation of Vibrationally Excited States in Solid Binary Carbonate-Sulfate Systems

    NASA Astrophysics Data System (ADS)

    Aliev, A. R.; Akhmedov, I. R.; Kakagasanov, M. G.; Aliev, Z. A.; Gafurov, M. M.; Rabadanov, K. Sh.; Amirov, A. M.

    2018-02-01

    The processes of molecular relaxation in solid binary carbonate-sulfate systems, such as Li2CO3-Li2SO4, Na2CO3-Na2SO4, K2CO3-K2SO4, have been studied by Raman spectroscopy. It has been revealed that the relaxation time of CO 3 2- anion vibration ν1(A) in a binary system is higher than in an individual carbonate. It is shown that an increase in the relaxation rate may be explained by the existence of an additional mechanism of the relaxation of vibrationally excited states of a carbonate anion. This mechanism is associated with the excitation of the vibration of another anion (SO 4 2- ) and the "birth" of a lattice phonon. It has been established that the condition for the implementation of such a relaxation mechanism is that the difference between the frequencies of these vibrations must correspond to the region of a rather high density of phonon spectrum states.

  9. Highly solid-state emissive pyridinium-substituted tetraphenylethylene salts: emission color-tuning with counter anions and application for optical waveguides.

    PubMed

    Hu, Fang; Zhang, Guanxin; Zhan, Chi; Zhang, Wei; Yan, Yongli; Zhao, Yongsheng; Fu, Hongbing; Zhang, Deqing

    2015-03-18

    In this paper seven salts of pyridinium-substituted tetraphenylethylene with different anions are reported. They show typical aggregation-induced emission. Crystal structures of three of the salts with (CF(3)SO(2))(2) N(-), CF(3) SO(3)(-), and SbF(6)(-) as the respective counter anions, are determined. The emission behavior of their amorphous and crystalline solids is investigated. Both amorphous and crystalline solids, except for the one with I(-), are highly emissive. Certain amorphous solids are red-emissive with almost the same quantum yields and fluorescence life-times. However, some crystalline solids are found to show different emission colors varying from green to yellow. Thus, their emission colors can be tuned by the counter anions. Furthermore, certain crystalline solids are highly emissive compared to the respective amorphous solids. Such solid-state emission behavior of these pyridinium-substituted tetraphenylethylene salts is interpreted on the basis of their crystal structures. In addition, optical waveguiding behavior of fabricated microrods is presented. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Syntheses, Raman spectroscopy and crystal structures of alkali hexa­fluorido­rhenates(IV) revisited

    PubMed Central

    Louis-Jean, James; Salamat, Ashkan; Pham, Chien Thang; Poineau, Frederic

    2018-01-01

    The A 2[ReF6] (A = K, Rb and Cs) salts are isotypic and crystallize in the trigonal space group type P m1, adopting the K2[GeF6] structure type. Common to all A 2[ReF6] structures are slightly distorted octa­hedral [ReF6]2− anions with an average Re—F bond length of 1.951 (8) Å. In those salts, symmetry lowering on the local [ReF6]2− anions from Oh (free anion) to D 3d (solid-state structure) occur. The distortions of the [ReF6]2− anions, as observed in their Raman spectra, are correlated to the size of the counter-cations.

  11. Fast oxygen diffusion in bismuth oxide probed by quasielastic neutron scattering

    DOE PAGES

    Mamontov, Eugene

    2016-09-24

    In this paper, we present the first, to our knowledge, study of solid state oxygen translational diffusion by quasielastic neutron scattering. Such studies in the past might have been precluded by relatively low diffusivities of oxygen anions in the temperature range amenable to neutron scattering experiments. To explore the potential of the quasielastic scattering technique, which can deduce atomic diffusion jump length of oxygen anions through the momentum transfer dependence of the scattering signal, we have selected the fastest known oxygen conductor, bismuth oxide. Finally, we have found the oxygen anion jump length in excellent agreement with the nearest oxygen-vacancymore » distance in the anion sublattice of the fluorite-related structure of bismuth oxide.« less

  12. Syntheses, Raman spectroscopy and crystal structures of alkali hexafluoridorhenates(IV) revisited

    DOE PAGES

    Louis-Jean, James; Mariappan Balasekaran, Samundeeswari; Smith, Dean; ...

    2018-04-06

    The A 2[ReF 6] (A = K, Rb and Cs) salts are isotypic and crystallize in the trigonal space group type Pmore » $$\\bar{3}$$m1, adopting the K 2[GeF 6] structure type. Common to all A 2[ReF 6] structures are slightly distorted octa­hedral [ReF 6] 2- anions with an average Re—F bond length of 1.951 (8) Å. In these salts, symmetry lowering on the local [ReF 6] 2- anions from O h (free anion) to D 3d (solid-state structure) occur. The distortions of the [ReF 6] 2- anions, as observed in their Raman spectra, are correlated to the size of the counter-cations.« less

  13. Simple guanidinium motif for the selective binding and extraction of sulfate

    DOE PAGES

    Seipp, Charles A.; Williams, Neil J.; Bryantsev, Vyacheslav S.; ...

    2017-06-30

    A simple bidentate anion receptor, shown previously to adopt a rigid pseudobicyclic conformation while binding anions in the solid state, selectively binds sulfate in aqueous solutions with logK1 and logK2 values of 3.78 ± 0.12 M-1 and 2.10 ± 0.23 M-1, respectively. This anion receptor has little to no affinity for nitrate and chloride in the same solutions. A lipophilic derivative was synthesized in four steps to yield an extractant that is capable of partitioning sulfate into 1,2 dichloroethane from water in the presence of large excesses of chloride. This extractant demonstrated D values as high as 2.5 with onlymore » 30 mM of anion receptor.« less

  14. Simple guanidinium motif for the selective binding and extraction of sulfate

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Seipp, Charles A.; Williams, Neil J.; Bryantsev, Vyacheslav S.

    A simple bidentate anion receptor, shown previously to adopt a rigid pseudobicyclic conformation while binding anions in the solid state, selectively binds sulfate in aqueous solutions with logK1 and logK2 values of 3.78 ± 0.12 M-1 and 2.10 ± 0.23 M-1, respectively. This anion receptor has little to no affinity for nitrate and chloride in the same solutions. A lipophilic derivative was synthesized in four steps to yield an extractant that is capable of partitioning sulfate into 1,2 dichloroethane from water in the presence of large excesses of chloride. This extractant demonstrated D values as high as 2.5 with onlymore » 30 mM of anion receptor.« less

  15. Structural Changes Fundamental to Gating of the Cystic Fibrosis Transmembrane Conductance Regulator Anion Channel Pore.

    PubMed

    Linsdell, Paul

    2017-01-01

    Cystic fibrosis is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR), an epithelial cell anion channel. Potentiator drugs used in the treatment of cystic fibrosis act on the channel to increase overall channel function, by increasing the stability of its open state and/or decreasing the stability of its closed state. The structure of the channel in either the open state or the closed state is not currently known. However, changes in the conformation of the protein as it transitions between these two states have been studied using functional investigation and molecular modeling techniques. This review summarizes our current understanding of the architecture of the transmembrane channel pore that controls the movement of chloride and other small anions, both in the open state and in the closed state. Evidence for different kinds of changes in the conformation of the pore as it transitions between open and closed states is described, as well as the mechanisms by which these conformational changes might be controlled to regulate normal channel gating. The ways that key conformational changes might be targeted by small compounds to influence overall CFTR activity are also discussed. Understanding the changes in pore structure that might be manipulated by such small compounds is key to the development of novel therapeutic strategies for the treatment of cystic fibrosis.

  16. Study of organic radicals through anion photoelectron velocity-map imaging spectroscopy

    NASA Astrophysics Data System (ADS)

    Dixon, Andrew Robert

    We report preliminary results on the photoelectron imaging of phenylcarbene, cyanophenylcarbene, and chlorophenylcarbene anions. Triplet phenylcarbene is observed to have an EA of ≤ 0.83 eV, considerably lower than the previously indirectly-determined value. Transitions to the singlet and triplet ground state of both cyanophenylcarbene and chlorophenylcarbene are observable, though unidentified bands make full assignment difficult. Cyanophenylcarbene is found to have a triplet ground-state, with a tentative EA of 2.04 eV. Chlorophenylcarbene is found to have a singlet ground-state. The phenyl-group is found to favor the singlet state slightly. The cyanofluoromethyl radical, FC(H)CN, was estimated to have an EA of 1.53 +/- 0.08 eV, by a combination of experimental and theoretical results.. With similar methodology, we report the adiabatic electron affinity of the cyanobenzyl radical, EA(PhCHCN) = 1.90 +/- 0.01 eV, and assign an upper limit of the EA for the chlorobenzyl radical, EA(PhCHCl) ≤ 1.12 eV. These values were used to estimate the C-H bond dissociation energy (BDE)s for these substituted methanes. Fluoroacetonitrile was found to have a BDE of D H198 = 90.7 +/- 2.8 kcal mol□1. The C-H bond dissociation energies at the benzyl-alpha sites of the phenylmethanes are determined as 80.9 +/- 2.3 kcal mol-1 for benzyl nitrile and an upper limit of 84.2 kcal mol-1 for benzyl chloride. These results are discussed in terms of substituent interactions in a simple MO framework and in relation to other similar molecules, including recently reported results for chloroacetonitrile. The 532 nm photoelectron spectrum of glyoxal provides the first direct spectroscopic determination of the adiabatic electron affinity, EA = 1.10(2) eV. This assignment is supported by a Franck-Condon simulation of the experimental spectrum that successfully reproduces the observed spectral features. The vertical detachment energy (VDE) of the glyoxal radical anion is determined as VDE = 1.30(4) eV. The EA of methylglyoxal is determined as ≤ 0.8 eV based on the signal-to-noise ratio of the X 1A ' ← X 2A'' transition, with a VDE = 1.28(4) eV. The EA of the a 3A'' ← X 2A '' and A 1A'' ← X 2A'' transitions are determined as 3.28(3) eV and 3.614(5) eV respectively. The intrinsically short-lived ethylenedione molecule (OCCO) was observed and investigated using anion photoelectron spectroscopy. The adiabatic electron affinity of its 3Sigmag □ ground state is 1.936(8) eV. The vibrational progression with a 417(15) cm-1 frequency observed within the triplet band corresponds to a trans-bending mode. Several dissociative singlet states are also observed, corresponding to two components of the 1Delta g state and the 1Sigmag + state. The experimental results are in agreement with the theory predictions and constitute the first spectroscopic observation and characterization of the elusive ethylenedione molecule. Two glyoxal derivatives related to the ethylenedione anion (OCCO -), ethynediolide (HOCCO-) and glyoxalide (OHCCO-), were studied. These anions provide access to the corresponding neutral reactive intermediates: the HOCCO and OHCCO radicals. In the HOCCO/OHCCO anion photoelectron spectrum, we identify several electronic states of this radical system and determine the adiabatic electron affinity of HOCCO as 1.763(6) eV. This result is compared to the corresponding 1.936(8) eV value for ethylenedione (OCCO). Initial attempts were made to detect and observe the dicyanoacetylene anion, NCCCCN- , by photoelectron imaging. While it is believed the experimental design path of H2+ abstraction from fumaronitrile is sound, no spectral signature can be assigned to NCCCCN -. Calculations targeting the low-lying transitions from the anion indicate that the molecule should have a significantly positive electron affinity and at least the ground state should be accessible with the currently available laser sources. The cluster ion O2(N2O) of the same nominal mass as NCCCCN- is identified as an interfering ion and ideas have been proposed for resolving this difficulty. (Abstract shortened by ProQuest.).

  17. Electron affinity and excited states of methylglyoxal

    NASA Astrophysics Data System (ADS)

    Dauletyarov, Yerbolat; Dixon, Andrew R.; Wallace, Adam A.; Sanov, Andrei

    2017-07-01

    Using photoelectron imaging spectroscopy, we characterized the anion of methylglyoxal (X2A″ electronic state) and three lowest electronic states of the neutral methylglyoxal molecule: the closed-shell singlet ground state (X1A'), the lowest triplet state (a3A″), and the open-shell singlet state (A1A″). The adiabatic electron affinity (EA) of the ground state, EA(X1A') = 0.87(1) eV, spectroscopically determined for the first time, compares to 1.10(2) eV for unsubstituted glyoxal. The EAs (adiabatic attachment energies) of two excited states of methylglyoxal were also determined: EA(a3A″) = 3.27(2) eV and EA(A1A″) = 3.614(9) eV. The photodetachment of the anion to each of these two states produces the neutral species near the respective structural equilibria; hence, the a3A″ ← X2A″ and A1A″ ← X2A″ photodetachment transitions are dominated by intense peaks at their respective origins. The lowest-energy photodetachment transition, on the other hand, involves significant geometry relaxation in the X1A' state, which corresponds to a 60° internal rotation of the methyl group, compared to the anion structure. Accordingly, the X1A' ← X2A″ transition is characterized as a broad, congested band, whose vertical detachment energy, VDE = 1.20(4) eV, significantly exceeds the adiabatic EA. The experimental results are in excellent agreement with the ab initio predictions using several equation-of-motion methodologies, combined with coupled-cluster theory.

  18. Electron propagator calculations on the ionization energies of CrH -, MnH - and FeH -

    NASA Astrophysics Data System (ADS)

    Lin, Jyh-Shing; Ortiz, J. V.

    1990-08-01

    Electron propagator calculations with unrestricted Hartree-Fock reference states yield the ionization energies of the title anions. Spin contamination in the anionic reference state is small, enabling the use of second-and third-order self-energies in the Dyson equation. Feynman-Dyson amplitudes for these ionizations are essentially identical to canonical spin-orbitals. For most of the final states, these consist of an antibonding combination of an sp metal hybrid, polarized away from the hydrogen, and hydroegen s functions. In one case, the Feynman-Dyson amplitude consists of nonbonding d functions. Calculated ionization energies are within 0.5 eV of experiment.

  19. Ionization and Anion-π+ Interaction: A New Strategy for Structural Design of Aggregation-Induced Emission Luminogens.

    PubMed

    Wang, Jianguo; Gu, Xinggui; Zhang, Pengfei; Huang, Xiaobo; Zheng, Xiaoyan; Chen, Ming; Feng, Haitao; Kwok, Ryan T K; Lam, Jacky W Y; Tang, Ben Zhong

    2017-11-22

    Recent years have witnessed the significant role of anion-π + interactions in many areas, which potentially brings the opportunity for the development of aggregation-induced emission (AIE) systems. Here, a new strategy that utilized anion-π + interactions to block detrimental π-π stacking was first proposed to develop inherent-charged AIE systems. Two AIE-active luminogens, namely, 1,2,3,4-tetraphenyloxazolium (TPO-P) and 2,3,5-triphenyloxazolium (TriPO-PN), were successfully synthesized. Comprehensive techniques such as single-crystal analysis, theoretical calculation, and conductivity measurement were used to illustrate the effects of anion-π + interactions on the AIE feature. Their analogues tetraphenylfuran (TPF) and 2,4,5-triphenyloxazole (TriPO-C) without anion-π + interactions suffered from the aggregation-caused emission quenching in the aggregate state, demonstrating the important role of anion-π + interactions in suppressing π-π stacking. TriPO-PN was biocompatible and could specifically target lysosome in fluorescence turn-on and wash-free manners. This suggested that it was a promising contrast agent for bioimaging.

  20. Conformational Preference of ‘CαNN’ Short Peptide Motif towards Recognition of Anions

    PubMed Central

    Banerjee, Raja

    2013-01-01

    Among several ‘anion binding motifs’, the recently described ‘CαNN’ motif occurring in the loop regions preceding a helix, is conserved through evolution both in sequence and its conformation. To establish the significance of the conserved sequence and their intrinsic affinity for anions, a series of peptides containing the naturally occurring ‘CαNN’ motif at the N-terminus of a designed helix, have been modeled and studied in a context free system using computational techniques. Appearance of a single interacting site with negative binding free-energy for both the sulfate and phosphate ions, as evidenced in docking experiments, establishes that the ‘CαNN’ segment has an intrinsic affinity for anions. Molecular Dynamics (MD) simulation studies reveal that interaction with anion triggers a conformational switch from non-helical to helical state at the ‘CαNN’ segment, which extends the length of the anchoring-helix by one turn at the N-terminus. Computational experiments substantiate the significance of sequence/structural context and justify the conserved nature of the ‘CαNN’ sequence for anion recognition through “local” interaction. PMID:23516403

  1. 75 FR 43090 - Fisheries of the Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-23

    ...: Temporary rule; correction. SUMMARY: NMFS is correcting a temporary rule to adjust the 2010 fishing year (FY... revised Trimester 3 quota. The correct value for the revised Trimester 3 quota of 23,743,619 lb is 10,770... equivalent as 13,770 mt. The corrected metric equivalent is 10,770 mt. Correction In rule FR Doc. 2010-15933...

  2. 26 CFR 1.904(g)-2T - Recapture of overall domestic losses (temporary).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...). 1.904(g)-2T Section 1.904(g)-2T Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE... States § 1.904(g)-2T Recapture of overall domestic losses (temporary). (a) In general. A taxpayer shall... increased. As provided in § 1.904(g)-1T(f)(2), the balance in a taxpayer's overall domestic loss account...

  3. 26 CFR 1.904(g)-1T - Overall domestic loss and the overall domestic loss account (temporary).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... loss account (temporary). 1.904(g)-1T Section 1.904(g)-1T Internal Revenue INTERNAL REVENUE SERVICE... Without the United States § 1.904(g)-1T Overall domestic loss and the overall domestic loss account... reductions from such accounts for purposes of section 904(g). Section 1.904(g)-2T provides rules for...

  4. 26 CFR 1.904(g)-1T - Overall domestic loss and the overall domestic loss account (temporary).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... loss account (temporary). 1.904(g)-1T Section 1.904(g)-1T Internal Revenue INTERNAL REVENUE SERVICE... Without the United States § 1.904(g)-1T Overall domestic loss and the overall domestic loss account... reductions from such accounts for purposes of section 904(g). Section 1.904(g)-2T provides rules for...

  5. 26 CFR 1.904(g)-2T - Recapture of overall domestic losses (temporary).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...). 1.904(g)-2T Section 1.904(g)-2T Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE... States § 1.904(g)-2T Recapture of overall domestic losses (temporary). (a) In general. A taxpayer shall... increased. As provided in § 1.904(g)-1T(f)(2), the balance in a taxpayer's overall domestic loss account...

  6. A joint modelling approach for multistate processes subject to resolution and under intermittent observations.

    PubMed

    Yiu, Sean; Tom, Brian

    2017-02-10

    Multistate processes provide a convenient framework when interest lies in characterising the transition intensities between a set of defined states. If, however, there is an unobserved event of interest (not known if and when the event occurs), which when it occurs stops future transitions in the multistate process from occurring, then drawing inference from the joint multistate and event process can be problematic. In health studies, a particular example of this could be resolution, where a resolved patient can no longer experience any further symptoms, and this is explored here for illustration. A multistate model that includes the state space of the original multistate process but partitions the state representing absent symptoms into a latent absorbing resolved state and a temporary transient state of absent symptoms is proposed. The expanded state space explicitly distinguishes between resolved and temporary spells of absent symptoms through disjoint states and allows the uncertainty of not knowing if resolution has occurred to be easily captured when constructing the likelihood; observations of absent symptoms can be considered to be temporary or having resulted from resolution. The proposed methodology is illustrated on a psoriatic arthritis data set where the outcome of interest is a set of intermittently observed disability scores. Estimated probabilities of resolving are also obtained from the model. © 2016 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd. © 2016 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.

  7. [Temporary work].

    PubMed

    Del Forno, E; Candura, F

    2002-01-01

    In recent years, labour market has really changed in Italy: in addition to traditional categories of workers, self-governing or subordinate, a "tertium genus" was born, that of "temporary workers". This new modality allows firms which need to introduce temporary workers in production processes, to find them through the activity of skilled intermediary agencies. This type of agencies, regularly authorized by the Ministry of Labour, was born to select subordinates, who will work in other firms, without engagement. (The low which regulates temporary work in Italy is the Act n. 196 of 1997). The subject analysed the most closely in the text, is the really interesting question of responsibility for prevention, safety and health in work places: in fact, temporary work creates a complex system of bilateral relations, but the only real work contract is between provider firms and temporary workers. The Act n. 196 states that the provider firm must fulfill its duties of contribution, security, aid and insurance against industrial accidents and occupational diseases. Therefore, according to a series of argumentations developed in the text, only the occupational health consultant designated by the temporary agency is reasonably responsible for medical supervision, but he has to coordinate and collaborate with the occupational health consultant of third firms (Directive 383 of 1991 and article 7 of Legislative Decree n. 626 of 1994). On the contrary, firms which need temporary workers, must fulfill duties of information and training for workers. As a consequence, to draw a conclusion, on the ground of principles of European Union and national laws (in force since '50s in this field), the responsibility for medical supervision falls on temporary agencies; on the contrary, economic responsibility falls on firms which request workers, in order to achieve protection of workers' health.

  8. 20 CFR 655.35 - Required departure.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process and Enforcement of Attestations for Temporary Employment in Occupations Other Than Agriculture or Registered Nursing in the United States (H-2B...

  9. 20 CFR 655.30 - Supervised recruitment.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process and Enforcement of Attestations for Temporary Employment in Occupations Other Than Agriculture or Registered Nursing in the United States (H-2B...

  10. Aryl C—H···Cl– Hydrogen Bonding in a Fluorescent Anion Sensor

    PubMed Central

    Tresca, Blakely W.; Zakharov, Lev N.; Carroll, Calden N.; Johnson, Darren W.; Haley, Michael M.

    2014-01-01

    A new phenyl-acetylene receptor containing a carbonaceous hydrogen bond donor activates anion binding in conjunction with two stabilizing ureas. The unusual CH···Cl– hydrogen bond is apparent in solution by large 1H NMR chemical shifts and by a short, linear contact in the solid state. PMID:23843050

  11. An anion-immobilized composite electrolyte for dendrite-free lithium metal anodes

    PubMed Central

    Zhao, Chen-Zi; Zhang, Xue-Qiang; Cheng, Xin-Bing; Zhang, Rui; Xu, Rui; Chen, Peng-Yu; Peng, Hong-Jie; Huang, Jia-Qi

    2017-01-01

    Lithium metal is strongly regarded as a promising electrode material in next-generation rechargeable batteries due to its extremely high theoretical specific capacity and lowest reduction potential. However, the safety issue and short lifespan induced by uncontrolled dendrite growth have hindered the practical applications of lithium metal anodes. Hence, we propose a flexible anion-immobilized ceramic–polymer composite electrolyte to inhibit lithium dendrites and construct safe batteries. Anions in the composite electrolyte are tethered by a polymer matrix and ceramic fillers, inducing a uniform distribution of space charges and lithium ions that contributes to a dendrite-free lithium deposition. The dissociation of anions and lithium ions also helps to reduce the polymer crystallinity, rendering stable and fast transportation of lithium ions. Ceramic fillers in the electrolyte extend the electrochemically stable window to as wide as 5.5 V and provide a barrier to short circuiting for realizing safe batteries at elevated temperature. The anion-immobilized electrolyte can be applied in all–solid-state batteries and exhibits a small polarization of 15 mV. Cooperated with LiFePO4 and LiNi0.5Co0.2Mn0.3O2 cathodes, the all–solid-state lithium metal batteries render excellent specific capacities of above 150 mAh⋅g−1 and well withstand mechanical bending. These results reveal a promising opportunity for safe and flexible next-generation lithium metal batteries. PMID:28973945

  12. Atomic solid state energy scale: Universality and periodic trends in oxidation state

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Pelatt, Brian D.; Kokenyesi, Robert S.; Ravichandran, Ram

    2015-11-15

    The atomic solid state energy (SSE) scale originates from a plot of the electron affinity (EA) and ionization potential (IP) versus band gap (E{sub G}). SSE is estimated for a given atom by assessing an average EA (for a cation) or an average IP (for an anion) for binary inorganic compounds having that specific atom as a constituent. Physically, SSE is an experimentally-derived average frontier orbital energy referenced to the vacuum level. In its original formulation, 69 binary closed-shell inorganic semiconductors and insulators were employed as a database, providing SSE estimates for 40 elements. In this contribution, EA and IPmore » versus E{sub G} are plotted for an additional 92 compounds, thus yielding SSE estimates for a total of 64 elements from the s-, p-, d-, and f-blocks of the periodic table. Additionally, SSE is refined to account for its dependence on oxidation state. Although most cations within the SSE database are found to occur in a single oxidation state, data are available for nine d-block transition metals and one p-block main group metal in more than one oxidation state. SSE is deeper in energy for a higher cation oxidation state. Two p-block main group non-metals within the SSE database are found to exist in both positive and negative oxidation states so that they can function as a cation or anion. SSEs for most cations are positioned above −4.5 eV with respect to the vacuum level, and SSEs for all anions are positioned below. Hence, the energy −4.5 eV, equal to the hydrogen donor/acceptor ionization energy ε(+/−) or equivalently the standard hydrogen electrode energy, is considered to be an absolute energy reference for chemical bonding in the solid state. - Highlights: • Atomic solid-state energies are estimated for 64 elements from experimental data. • The relationship between atomic SSEs and oxidation state is assessed. • Cations are positioned above and absolute energy of −4.5 eV and anions below.« less

  13. Imidazolium-based Block Copolymers as Solid-State Separators for Alkaline Fuel Cells and Lithium Ion Batteries

    NASA Astrophysics Data System (ADS)

    Nykaza, Jacob Richard

    In this study, polymerized ionic liquid (PIL) diblock copolymers were explored as solid-state polymer separators as an anion exchange membrane (AEM) for alkaline fuel cells AFCs and as a solid polymer electrolyte (SPE) for lithium-ion batteries. Polymerized ionic liquid (PIL) block copolymers are a distinct set of block copolymers that combine the properties of both ionic liquids (e.g., high conductivity, high electrochemical stability) and block copolymers (e.g., self-assembly into various nanostructures), which provides the opportunity to design highly conductive robust solid-state electrolytes that can be tuned for various applications including AFCs and lithium-ion batteries via simple anion exchange. A series of bromide conducting PIL diblock copolymers with an undecyl alkyl side chain between the polymer backbone and the imidazolium moiety were first synthesized at various compositions comprising of a PIL component and a non-ionic component. Synthesis was achieved by post-functionalization from its non-ionic precursor PIL diblock copolymer, which was synthesized via the reverse addition fragmentation chain transfer (RAFT) technique. This PIL diblock copolymer with long alkyl side chains resulted in flexible, transparent films with high mechanical strength and high bromide ion conductivity. The conductivity of the PIL diblock copolymer was three times higher than its analogous PIL homopolymer and an order of magnitude higher than a similar PIL diblock copolymer with shorter alkyl side chain length, which was due to the microphase separated morphology, more specifically, water/ion clusters within the PIL microdomains in the hydrated state. Due to the high conductivity and mechanical robustness of this novel PIL block copolymer, its application as both the ionomer and AEM in an AFC was investigated via anion exchange to hydroxide (OH-), where a maximum power density of 29.3 mW cm-1 (60 °C with H2/O2 at 25 psig (172 kPa) backpressure) was achieved. Rotating disk electrode (RDE) experiments determined the interfacial resistance imposed during cell assembly between the AEM, catalyst, and ionomer was a factor in fuel cell performance. Further RDE studies investigated the electrochemical stability of the PIL block copolymer ionomer under applied potentials, where it was determined that potential cycling increased the degradation compared to constant voltage or open circuit voltage studies. The PIL diblock copolymer was then anion exchanged to the bis(trifluoromethane)sulfonamide (TFSI-) anion form and imbibed with a lithium salt and ionic liquid solution for use as a SPE in lithium-ion batteries resulting in a maximum discharge capacity of 112 mAh g-1 at 0.1 C with a Coulombic efficiency greater than 94% over 100 cycles. PIL block copolymers have promising mechanical properties and transport properties (i.e., ion conductivity) in both the hydrated (hydrophilic anions; Br-, OH-) and dry (hydrophobic anions; TFSI-) states resulting in highly conductive, chemically/thermally stable, and mechanically robust solid-state polymer separators for use as AEMs in AFCs and as SPEs in lithium-ion batteries.

  14. 20 CFR 655.2 - Territory of Guam.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process and Enforcement of Attestations for Temporary Employment in Occupations Other Than Agriculture or Registered Nursing in the United States (H-2B...

  15. 20 CFR 655.74 - Conduct of proceedings.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process and Enforcement of Attestations for Temporary Employment in Occupations Other Than Agriculture or Registered Nursing in the United States (H-2B...

  16. 20 CFR 655.60 - Violations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... WORKERS IN THE UNITED STATES Labor Certification Process and Enforcement of Attestations for Temporary Employment in Occupations Other Than Agriculture or Registered Nursing in the United States (H-2B Workers... application process. ...

  17. 20 CFR 655.7-655.9 - [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process and Enforcement of Attestations for Temporary Employment in Occupations Other Than Agriculture or Registered Nursing in the United States (H-2B...

  18. 20 CFR 655.71 - Request for hearing.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process and Enforcement of Attestations for Temporary Employment in Occupations Other Than Agriculture or Registered Nursing in the United States (H-2B...

  19. 20 CFR 655.73 - Service of pleadings.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process and Enforcement of Attestations for Temporary Employment in Occupations Other Than Agriculture or Registered Nursing in the United States (H-2B...

  20. 6 CFR 37.3 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... resident status in the United States; who has an approved application for asylum in the United States or... United States; who has a pending application for asylum in the United States; who has a pending or approved application for temporary protected status (TPS) in the United States; who has approved deferred...

  1. 6 CFR 37.3 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... resident status in the United States; who has an approved application for asylum in the United States or... United States; who has a pending application for asylum in the United States; who has a pending or approved application for temporary protected status (TPS) in the United States; who has approved deferred...

  2. Anion Binding to Hydrophobic Concavity is Central to the Salting-in Effects of Hofmeister Chaotropes

    PubMed Central

    Gibb, Corinne L. D.; Gibb, Bruce C.

    2011-01-01

    For over 120 years it has been appreciated that certain salts (kosmotropes) cause the precipitation of proteins, whilst others (chaotropes) increase their solubility. The cause of this, “Hofmeister effect” is still unclear; especially with the original concept that kosmotropic anions “make” water structure and chaotropes “break” it being countered by recent studies suggesting otherwise. Here, we present the first direct evidence that chaotropic anions have an affinity for hydrophobic concavity, and that it is competition between a convex hydrophobe and the anion for a binding site that leads to the apparent weakening of the hydrophobic effect by chaotropes. In combination, these results suggest that chaotropes primarily induce protein solubilization by direct binding to concavity in the molten globule state of a protein. PMID:21524086

  3. Comparative Studies in the Fluorescence and Excitation Spectra of 3-Hydroxyflavone and 2(2 '-Heteroaryl)-3-Hydroxy-4H-Chromen-4-Ones

    NASA Astrophysics Data System (ADS)

    Kaur, R.; Kaur, K.; Bansal, M.

    2017-05-01

    The absorption, fluorescence, and excitation spectra of FHC and THC have been studied and compared with 3HF in cyclohexane, acetonitrile, and methanol. Anion formation in acetonitrile and methanol has been observed in all three flavonols in the order THC-FHC-3HF in their ground states. As excitation and absorption spectra are similar in all the cases (including the anion one), it is possible to observe the absorption spectra of the pure anion of the flavonols in neutral solvents, which is difficult to measure directly.

  4. Negative ions of p-nitroaniline: Photodetachment, collisions, and ab initio calculations

    NASA Astrophysics Data System (ADS)

    Smith, Byron H.; Buonaugurio, Angela; Chen, Jing; Collins, Evan; Bowen, Kit H.; Compton, Robert N.; Sommerfeld, Thomas

    2013-06-01

    The structures of parent anion, M-, and deprotonated molecule, [M-H]-, anions of the highly polar p-nitroaniline (pNA) molecule are studied experimentally and theoretically. Photoelectron spectroscopy (PES) of the parent anion is employed to estimate the adiabatic electron affinity (EAa = 0.75 ± 0.1 eV) and vertical detachment energy (VDE = 1.1 eV). These measured energies are in good agreement with computed values of 0.73 eV for the EAa and the range of 0.85 to 1.0 eV for the VDE at the EOM-CCSD/Aug-cc-pVTZ level. Collision induced dissociation (CID) of deprotonated pNA, [pNA - H]-, with argon yielded [pNA - H - NO]- (i.e., rearrangement to give loss of NO) with a threshold energy of 2.36 eV. Calculations of the energy difference between [pNA - H]- and [pNA - H - NO]- give 1.64 eV, allowing an estimate of a 0.72 eV activation barrier for the rearrangement reaction. Direct dissociation of [pNA - H]- yielding NO_2^ - occurs at a threshold energy of 3.80 eV, in good agreement with theory (between 3.39 eV and 4.30 eV). As a result of the exceedingly large dipole moment for pNA (6.2 Debye measured in acetone), we predict two dipole-bound states, one at ˜110 meV and an excited state at 2 meV. No dipole-bound states are observed in the photodetachment experiments due the pronounced mixing between states with dipole-bound and valence character similar to what has been observed in other nitro systems. For the same reason, dipole-bound states are expected to provide highly efficient "doorway states" for the formation of the pNA- valence anion, and these states should be observable as resonances in the reverse process, that is, in the photodetachment spectrum of pNA- near the photodetachment threshold.

  5. Negative ions of p-nitroaniline: photodetachment, collisions, and ab initio calculations.

    PubMed

    Smith, Byron H; Buonaugurio, Angela; Chen, Jing; Collins, Evan; Bowen, Kit H; Compton, Robert N; Sommerfeld, Thomas

    2013-06-21

    The structures of parent anion, M(-), and deprotonated molecule, [M-H](-), anions of the highly polar p-nitroaniline (pNA) molecule are studied experimentally and theoretically. Photoelectron spectroscopy (PES) of the parent anion is employed to estimate the adiabatic electron affinity (EAa = 0.75 ± 0.1 eV) and vertical detachment energy (VDE = 1.1 eV). These measured energies are in good agreement with computed values of 0.73 eV for the EAa and the range of 0.85 to 1.0 eV for the VDE at the EOM-CCSD∕Aug-cc-pVTZ level. Collision induced dissociation (CID) of deprotonated pNA, [pNA - H](-), with argon yielded [pNA - H - NO](-) (i.e., rearrangement to give loss of NO) with a threshold energy of 2.36 eV. Calculations of the energy difference between [pNA - H](-) and [pNA - H - NO](-) give 1.64 eV, allowing an estimate of a 0.72 eV activation barrier for the rearrangement reaction. Direct dissociation of [pNA - H](-) yielding NO2(-) occurs at a threshold energy of 3.80 eV, in good agreement with theory (between 3.39 eV and 4.30 eV). As a result of the exceedingly large dipole moment for pNA (6.2 Debye measured in acetone), we predict two dipole-bound states, one at ~110 meV and an excited state at 2 meV. No dipole-bound states are observed in the photodetachment experiments due the pronounced mixing between states with dipole-bound and valence character similar to what has been observed in other nitro systems. For the same reason, dipole-bound states are expected to provide highly efficient "doorway states" for the formation of the pNA(-) valence anion, and these states should be observable as resonances in the reverse process, that is, in the photodetachment spectrum of pNA(-) near the photodetachment threshold.

  6. A delicate case of unidirectional proton transfer from water to an aromatic heterocyclic anion.

    PubMed

    Biswas, Sohag; Mallik, Bhabani S

    2016-11-21

    We present the characteristic proton transfer process from water to the pyrazole anion, infrared signatures of hydroxyl groups and the free energy profile of the process in aqueous solution combining first principles simulations, wavelet analysis and metadynamics. Our results show that the presence of minimum three water molecules in the gas phase cluster with a particular arrangement is sufficient to facilitate the proton transfer process from water to the anion. The overall reaction is very rapid in aqueous solution, and the free energy barrier for this process is found to be 4.2 kcal mol -1 . One of the earlier reported fundamental reasons for the transfer of proton from water to the anion is the change in the acidity of OH groups surrounding the anion. We have correlated the stretching frequencies of the surrounding OH groups with this acidity. We find that the development of less energetic vibrational states, and the OH mode having lowest average stretching frequency contains the most acidic proton. A large frequency shift of the OH mode belonging to one of the surrounding water molecules is observed during the transfer of proton from water to the anion; this shift is due to the change in acidity of the adjacent hydroxyl groups in the vicinity of the anion.

  7. Design principles for solid-state lithium superionic conductors.

    PubMed

    Wang, Yan; Richards, William Davidson; Ong, Shyue Ping; Miara, Lincoln J; Kim, Jae Chul; Mo, Yifei; Ceder, Gerbrand

    2015-10-01

    Lithium solid electrolytes can potentially address two key limitations of the organic electrolytes used in today's lithium-ion batteries, namely, their flammability and limited electrochemical stability. However, achieving a Li(+) conductivity in the solid state comparable to existing liquid electrolytes (>1 mS cm(-1)) is particularly challenging. In this work, we reveal a fundamental relationship between anion packing and ionic transport in fast Li-conducting materials and expose the desirable structural attributes of good Li-ion conductors. We find that an underlying body-centred cubic-like anion framework, which allows direct Li hops between adjacent tetrahedral sites, is most desirable for achieving high ionic conductivity, and that indeed this anion arrangement is present in several known fast Li-conducting materials and other fast ion conductors. These findings provide important insight towards the understanding of ionic transport in Li-ion conductors and serve as design principles for future discovery and design of improved electrolytes for Li-ion batteries.

  8. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mirjankar, Nikhil S.; Fraga, Carlos G.; Carman, April J.

    Chemical attribution signatures (CAS) for chemical threat agents (CTAs) are being investigated to provide an evidentiary link between CTAs and specific sources to support criminal investigations and prosecutions. In a previous study, anionic impurity profiles developed using high performance ion chromatography (HPIC) were demonstrated as CAS for matching samples from eight potassium cyanide (KCN) stocks to their reported countries of origin. Herein, a larger number of solid KCN stocks (n = 13) and, for the first time, solid sodium cyanide (NaCN) stocks (n = 15) were examined to determine what additional sourcing information can be obtained through anion, carbon stablemore » isotope, and elemental analyses of cyanide stocks by HPIC, isotope ratio mass spectrometry (IRMS), and inductively coupled plasma optical emission spectroscopy (ICP-OES), respectively. The HPIC anion data was evaluated using the variable selection methods of Fisher-ratio (F-ratio), interval partial least squares (iPLS), and genetic algorithm-based partial least squares (GAPLS) and the classification methods of partial least squares discriminate analysis (PLSDA), K nearest neighbors (KNN), and support vector machines discriminate analysis (SVMDA). In summary, hierarchical cluster analysis (HCA) of anion impurity profiles from multiple cyanide stocks from six reported country of origins resulted in cyanide samples clustering into three groups: Czech Republic, Germany, and United States, independent of the associated alkali metal (K or Na). The three country groups were independently corroborated by HCA of cyanide elemental profiles and corresponded to countries with known solid cyanide factories. Both the anion and elemental CAS are believed to originate from the aqueous alkali hydroxides used in cyanide manufacture. Carbon stable isotope measurements resulted in two clusters: Germany and United States (the single Czech stock grouped with United States stocks). The carbon isotope CAS is believed to originate from the carbon source and process used to make the HCN utilized in cyanide synthesis. Classification errors for two validation studies using anion impurity profiles collected over five years on different instruments were as low as zero for KNN and SVMDA, demonstrating the excellent reliability (so far) of using anion impurities for matching a cyanide sample to its country of manufacture (i.e., factory). Variable selection reduced errors for those classification methods having errors greater than zero with iPLS-forward selection, and F-ratio typically providing the lowest errors. Finally, using anion profiles to match cyanides to a specific stock or stock group resulted in cross-validation errors ranging from zero to 5.3%.« less

  9. 77 FR 27669 - Modifications to Definition of United States Property

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-11

    ... Modifications to Definition of United States Property AGENCY: Internal Revenue Service (IRS), Treasury. ACTION... contracts. The temporary regulations provide that certain obligations of United States persons arising from... derivatives clearing organization or clearing agency do not constitute United States property. The text of the...

  10. Anion Binding and Transport by Prodigiosin and Its Analogs

    NASA Astrophysics Data System (ADS)

    Davis, Jeffery T.

    The red-colored prodiginines, exemplified by prodigiosin 1, are secondary metabolites produced by a number of microorganisms, including the bacterium Serratia marcescens. These tripyrrole natural products and their synthetic analogs have received renewed attention over the past deacade, primarily because of their promising immunosuppressive and anticancer activities. One of the hallmarks of prodiginin chemistry is the ability of the monoprotonated ligand to bind anions, including the essential chloride and bicarbonate ions. The resulting lipophilic ion pair is then able to diffuse across the hydrophobic barrier presented by phospholipid bilayers. Thus, prodiginines have been found to be potent transmembrane anion transporters and HCl cotransporters. In this chapter, the author reviews what is known about the solid-state structure of prodiginins and their anion complexes, the solution conformation of prodiginines, and the biochemcal evidence for the ability to bind anions and to transport HCl across cell membranes. Recent progress in making synthetic models of prodiginines and recent results on the ability of prodigiosin to transport HCO 3 - across lipid membranes are discussed.

  11. Method of separating short half-life radionuclides from a mixture of radionuclides

    DOEpatents

    Bray, Lane A.; Ryan, Jack L.

    1999-01-01

    The present invention is a method of removing an impurity of plutonium, lead or a combination thereof from a mixture of radionuclides that contains the impurity and at least one parent radionuclide. The method has the steps of (a) insuring that the mixture is a hydrochloric acid mixture; (b) oxidizing the acidic mixture and specifically oxidizing the impurity to its highest oxidation state; and (c) passing the oxidized mixture through a chloride form anion exchange column whereupon the oxidized impurity absorbs to the chloride form anion exchange column and the 22.sup.9 Th or 2.sup.27 Ac "cow" radionuclide passes through the chloride form anion exchange column. The plutonium is removed for the purpose of obtaining other alpha emitting radionuclides in a highly purified form suitable for medical therapy. In addition to plutonium; lead, iron, cobalt, copper, uranium, and other metallic cations that form chloride anionic complexes that may be present in the mixture; are removed from the mixture on the chloride form anion exchange column.

  12. Method of separating short half-life radionuclides from a mixture of radionuclides

    DOEpatents

    Bray, L.A.; Ryan, J.L.

    1999-03-23

    The present invention is a method of removing an impurity of plutonium, lead or a combination thereof from a mixture of radionuclides that contains the impurity and at least one parent radionuclide. The method has the steps of (a) insuring that the mixture is a hydrochloric acid mixture; (b) oxidizing the acidic mixture and specifically oxidizing the impurity to its highest oxidation state; and (c) passing the oxidized mixture through a chloride form anion exchange column whereupon the oxidized impurity absorbs to the chloride form anion exchange column and the {sup 229}Th or {sup 227}Ac ``cow`` radionuclide passes through the chloride form anion exchange column. The plutonium is removed for the purpose of obtaining other alpha emitting radionuclides in a highly purified form suitable for medical therapy. In addition to plutonium, lead, iron, cobalt, copper, uranium, and other metallic cations that form chloride anionic complexes that may be present in the mixture are removed from the mixture on the chloride form anion exchange column. 8 figs.

  13. 20 CFR 655.80 - Notice to OFLC and DHS.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process and Enforcement of Attestations for Temporary Employment in Occupations Other Than Agriculture or Registered Nursing in the United States (H-2B...

  14. Self-organized criticality in asymmetric exclusion model with noise for freeway traffic

    NASA Astrophysics Data System (ADS)

    Nagatani, Takashi

    1995-02-01

    The one-dimensional asymmetric simple-exclusion model with open boundaries for parallel update is extended to take into account temporary stopping of particles. The model presents the traffic flow on a highway with temporary deceleration of cars. Introducing temporary stopping into the asymmetric simple-exclusion model drives the system asymptotically into a steady state exhibiting a self-organized criticality. In the self-organized critical state, start-stop waves (or traffic jams) appear with various sizes (or lifetimes). The typical interval < s>between consecutive jams scales as < s> ≃ Lv with v = 0.51 ± 0.05 where L is the system size. It is shown that the cumulative jam-interval distribution Ns( L) satisfies the finite-size scaling form ( Ns( L) ≃ L- vf( s/ Lv). Also, the typical lifetime ≃ Lv‧ with v‧ = 0.52 ± 0.05. The cumulative distribution Nm( L) of lifetimes satisfies the finite-size scaling form Nm( L)≃ L-1g( m/ Lv‧).

  15. Medicare, Medicaid, and Children's Health Insurance Programs: Announcement of the Extension of Temporary Moratoria on Enrollment of Part B Non-Emergency Ground Ambulance Suppliers and Home Health Agencies in Designated Geographic Locations. Extension of temporary moratoria.

    PubMed

    2018-01-30

    This document announces the extension of statewide temporary moratoria on the enrollment of new Medicare Part B non-emergency ground ambulance providers and suppliers and Medicare home health agencies, subunits, and branch locations in Florida, Illinois, Michigan, Texas, Pennsylvania, and New Jersey, as applicable, to prevent and combat fraud, waste, and abuse. This extension also applies to the enrollment of new non-emergency ground ambulance suppliers and home health agencies, subunits, and branch locations in Medicaid and the Children's Health Insurance Program in those states. For purposes of these moratoria, providers that were participating as network providers in one or more Medicaid managed care organizations prior to January 1, 2018 will not be considered "newly enrolling" when they are required to enroll with the State Medicaid agency pursuant to a new statutory requirement, and thus will not be subject to the moratoria.

  16. A versatile tripodal amide receptor for the encapsulation of anions or hydrated anions via formation of dimeric capsules.

    PubMed

    Arunachalam, M; Ghosh, Pradyut

    2010-02-01

    A bowl-shaped tripodal receptor with an appropriately positioned amide functionality on the benzene platform and electron-withdrawing p-nitrophenyl terminals (L(1)) has been designed, synthesized, and studied for the anion binding properties. The single-crystal X-ray crystallographic analysis on crystals of L(1) with tetrabutylammonium salts of nitrate (1), acetate (2), fluoride (3), and chloride (4) obtained in moist dioxane medium showed encapsulation of two NO(3)(-), [(AcO)(2)(H(2)O)(4)](2-), [F(2)(H(2)O)(6)](2-), and [Cl(2)(H(2)O)(4)](2-) respectively as the anionic guests inside the staggered dimeric capsular assembly of L(1). The p-nitro substitution in the aryl terminals assisted the formation of dimeric capsular assembly of L(1) exclusively upon binding/encapsulating above different guests. Though L(1) demonstrates capsule formation upon anion or hydrated anion complexation for all of the anions studied here, its positional isomer with the o-nitro-substituted tripodal triamide receptor L(2) selectively formed the dimeric capsular assembly upon encapsulation of [F(2)(H(2)O)(6)](2-) and noncapsular aggregates in the cases of other anions such as Cl(-), NO(3)(-), and AcO(-). Interestingly, structural investigations upon anion exchange of the complexes revealed that both isomers have selectivity toward the formation of a [F(2)(H(2)O)(6)](2-) encapsulated dimeric capsule. In contrast, solution-state (1)H NMR titration studies of L(1) and L(2) in DMSO-d(6) with AcO(-) indicated 1:3 (host:guest) binding.

  17. Influence of ionization states of antigen on anti-fluorescein antibodies

    NASA Astrophysics Data System (ADS)

    Fukunishi, Hiroaki

    2012-10-01

    Ratios of anion and di-anion states of fluorescein (FLU(-1) and FLU(-2)) are 21.2% and 78.8%, respectively, in the neutral pH. We investigated the influence of ionization states of antigen on anti-fluorescein antibodies. For this purpose, steered molecular dynamics (SMD) simulations were performed. Potential of mean forces (PMF) based on Jarzynski equality showed that wild-type (4-4-20) more strongly binds to FLU(-1) than FLU(-2), whereas its femtomolar-affinity mutant (4M5.3) more strongly binds to FLU(-2) than FLU(-1). It was speculated that the environment or the process of in vivo antibody production had been different from those of the protein engineering.

  18. Medicare, Medicaid, and Children's Health Insurance Programs: Announcement of the Extension of Temporary Moratoria on Enrollment of Part B Non-Emergency Ground Ambulance Suppliers and Home Health Agencies in Designated Geographic Locations. Extension of temporary moratoria.

    PubMed

    2017-07-28

    This document announces the extension of statewide temporary moratoria on the enrollment of new Medicare Part B non-emergency ground ambulance providers and suppliers and Medicare home health agencies, subunits, and branch locations in Florida, Illinois, Michigan, Texas, Pennsylvania, and New Jersey, as applicable, to prevent and combat fraud, waste, and abuse. This extension also applies to the enrollment of new non-emergency ground ambulance suppliers and home health agencies, subunits, and branch locations in Medicaid and the Children's Health Insurance Program in those states.

  19. Superconductivity of Ca2 InN with a layered structure embedding an anionic indium chain array

    NASA Astrophysics Data System (ADS)

    Jeong, Sehoon; Matsuishi, Satoru; Lee, Kimoon; Toda, Yoshitake; Wng Kim, Sung; Hosono, Hideo

    2014-05-01

    We report the emergence of superconductivity in Ca2InN consisting of a two-dimensional (2D) array of zigzag indium chains embedded between Ca2N layers. A sudden drop of resistivity and a specific heat (Cp) jump attributed to the superconducting transition were observed at 0.6 K. The Sommerfeld coefficient γ = 4.24 mJ mol-1K-2 and Debye temperature ΘD = 322 K were determined from the Cp of the normal conducting state and the superconducting volume fraction was estimated to be ˜80% from the Cp jump, assuming a BCS-type weak coupling. Density functional theory calculations demonstrated that the electronic bands near the Fermi level (EF) are mainly derived from In 5p orbitals with π and σ bonding states and the Fermi surface is composed of cylindrical parts, corresponding to the quasi-2D electronic state of the In-chain array. By integrating the projected density of states of the In-p component up to EF, a valence electron population of ˜1.6 electrons/In was calculated, indicating that partially anionic state of In. The In 3d binding energies observed in Ca2InN by x-ray photoemission spectroscopy were negatively shifted from that in In metal. The superconductivity of Ca2InN is associated with the p-p bonding states of the anionic In layer.

  20. Cyclopropenyl Anions: Carbon Tunneling or Diradical Formation? A Contest between Jahn-Teller and Hund.

    PubMed

    Kozuch, Sebastian

    2015-07-14

    The π bond shifting (automerization) by carbon tunneling of cyclopropenyl anions was computationally analyzed by the small curvature tunneling methodology. Similar to other antiaromatic cases, the process is hindered by substituents departing from planarity, since these groups must be realigned along with the π bond shifting. With hydrogens as substituents the tunneling is extremely fast, in a case of both heavy and light atom tunneling. But, with more massive substituents (such as Me and F), and especially with longer groups (such as CN), the tunneling probability is reduced or even virtually canceled. The automerization of triphenylcyclopropyl anion by tunneling was supposed to be impossible due to the high mass of the phenyl groups. However, it was found that the ground state of this species is actually a D3h aromatic triplet, a single-well system that cannot undergo automerization. For this and other systems with π acceptor groups, the superposition of states that generates the second-order Jahn-Teller distortion is diminished, and by Hund's rule, the triplet results in the ground state.

  1. Occupational stress, job insecurity and perception of the health status in Italian teachers with stable or temporary employment.

    PubMed

    Forcella, L; Di Donato, A; Reversi, S; Fattorini, E; Boscolo, P

    2009-01-01

    The object of this study is to analyse job stress and insecurity and the perception of symptoms (health status) of 374 teachers (30 women and 74 men) with stable or temporary employment in schools in Pescara, a town in Central Italy. Job strain and job insecurity were analysed by an Italian version of the Karasek?s questionnaire, the perception of the health status by a 12 item test, and state and trait anxiety by STAI I and STAI II. There were no significant differences depending on the type of school. The young women with temporary contracts showed only higher levels of job insecurity than the women with stable employment, while those over 50 years old also showed more elevated values of job strain. Men with temporary contracts showed higher levels of both job insecurity and state and trait anxiety. The following highly significant correlations were observed: a) in women, job strain and perception of symptoms vs STAI I and STAI II (p<0.001); b) in men, job strain, job insecurity and perception of symptoms vs STAI II; job strain vs perception of symptoms as well as a negative correlation of decision latitude vs job insecurity, STAI I and STAI II (p<0.01). These results highlight differences in the perception of job insecurity between men and women. In particular, the decision latitude (skill decision + decision authority) plays an important role in men; temporary employment is mainly related to anxiety in men, while anxiety enhances the perception of poor health status mainly in women.

  2. Grotthuss Transport of Iodide in EMIM/I3 Ionic Crystal.

    PubMed

    McDaniel, Jesse G; Yethiraj, Arun

    2018-01-11

    Highly ionic environments can mediate unusual chemical reactions that would otherwise be considered impossible based on chemical intuition. For example, the formation of a chemical bond between two iodide anions to form a divalent polyiodide anion is seemingly prohibited due to Coulombic repulsion. Using ab initio molecular dynamics simulations, we show that in the 1-ethyl-3-methylimidazolium (EMIM)/I 3 ionic crystal, the reactive formation of divalent and even trivalent polyiodide anions occurs with extremely small energetic barriers, due to the electrostatic field of the ionic lattice. A practical consequence of this anomalous reactivity is that iodide anions are efficiently transported within the crystal through a "Grotthuss-exchange" mechanism involving bond-breaking and forming events. We characterize two distinct transport pathways, involving both I 4 2- and I 7 3- intermediates, with fast transport of iodide resulting from the release of an I - anion on the opposite side of the intermediate species from the initial bond formation. The ordered cation arrangement in the crystal provides the necessary electrostatic screening for close approach of anions, suggesting a new counterintuitive approach to obtain high ionic conductivity. This new design principle could be used to develop better solid-state electrolytes for batteries, fuel cells, and supercapacitors.

  3. Simultaneous Analysis of Monovalent Anions and Cations with a Sub-Microliter Dead-Volume Flow-Through Potentiometric Detector for Ion Chromatography

    PubMed Central

    Dumanli, Rukiye; Attar, Azade; Erci, Vildan; Isildak, Ibrahim

    2016-01-01

    A microliter dead-volume flow-through cell as a potentiometric detector is described in this article for sensitive, selective and simultaneous detection of common monovalent anions and cations in single column ion chromatography for the first time. The detection cell consisted of less selective anion- and cation-selective composite membrane electrodes together with a solid-state composite matrix reference electrode. The simultaneous separation and sensitive detection of sodium (Na+), potassium (K+), ammonium (NH4+), chloride (Cl−) and nitrate (NO3−) in a single run was achieved by using 98% 1.5 mM MgSO4 and 2% acetonitrile eluent with a mixed-bed ion-exchange separation column without suppressor column system. The separation and simultaneous detection of the anions and cations were completed in 6 min at the eluent flow-rate of 0.8 mL/min. Detection limits, at S/N = 3, were ranged from 0.2 to 1.0 µM for the anions and 0.3 to 3.0 µM for the cations, respectively. The developed method was successfully applied to the simultaneous determination of monovalent anions and cations in several environmental and biological samples. PMID:26786906

  4. Barrier-free proton transfer in the valence anion of 2'-deoxyadenosine-5'-monophosphate. II. A computational study.

    PubMed

    Kobyłecka, Monika; Gu, Jiande; Rak, Janusz; Leszczynski, Jerzy

    2008-01-28

    The propensity of four representative conformations of 2(')-deoxyadenosine-5(')-monophosphate (5(')-dAMPH) to bind an excess electron has been studied at the B3LYP6-31++G(d,p) level. While isolated canonical adenine does not support stable valence anions in the gas phase, all considered neutral conformations of 5(')-dAMPH form adiabatically stable anions. The type of an anionic 5(')-dAMPH state, i.e., the valence, dipole bound, or mixed (valence/dipole bound), depends on the internal hydrogen bond(s) pattern exhibited by a particular tautomer. The most stable anion results from an electron attachment to the neutral syn-south conformer. The formation of this anion is associated with a barrier-free proton transfer triggered by electron attachment and the internal rotation around the C4(')-C5(') bond. The adiabatic electron affinity of the a_south-syn anion is 1.19 eV, while its vertical detachment energy is 1.89 eV. Our results are compared with the photoelectron spectrum (PES) of 5(')-dAMPH(-) measured recently by Stokes et al., [J. Chem. Phys. 128, 044314 (2008)]. The computational VDE obtained for the most stable anionic structure matches well with the experimental electron binding energy region of maximum intensity. A further understanding of DNA damage might require experimental and computational studies on the systems in which purine nucleotides are engaged in hydrogen bonding.

  5. Barrier-free proton transfer in the valence anion of 2'-deoxyadenosine-5'-monophosphate. II. A computational study

    NASA Astrophysics Data System (ADS)

    Kobyłecka, Monika; Gu, Jiande; Rak, Janusz; Leszczynski, Jerzy

    2008-01-01

    The propensity of four representative conformations of 2'-deoxyadenosine-5'-monophosphate (5'-dAMPH) to bind an excess electron has been studied at the B3LYP /6-31++G(d,p) level. While isolated canonical adenine does not support stable valence anions in the gas phase, all considered neutral conformations of 5'-dAMPH form adiabatically stable anions. The type of an anionic 5'-dAMPH state, i.e., the valence, dipole bound, or mixed (valence/dipole bound), depends on the internal hydrogen bond(s) pattern exhibited by a particular tautomer. The most stable anion results from an electron attachment to the neutral syn-south conformer. The formation of this anion is associated with a barrier-free proton transfer triggered by electron attachment and the internal rotation around the C4'-C5' bond. The adiabatic electron affinity of the a&barbelow;south-syn anion is 1.19eV, while its vertical detachment energy is 1.89eV. Our results are compared with the photoelectron spectrum (PES) of 5'-dAMPH- measured recently by Stokes et al., [J. Chem. Phys. 128, 044314 (2008)]. The computational VDE obtained for the most stable anionic structure matches well with the experimental electron binding energy region of maximum intensity. A further understanding of DNA damage might require experimental and computational studies on the systems in which purine nucleotides are engaged in hydrogen bonding.

  6. Aromatic aldehyde-catalyzed gas-phase decarboxylation of amino acid anion via imine intermediate: An experimental and theoretical study

    NASA Astrophysics Data System (ADS)

    Xiang, Zhang

    2013-10-01

    It is generally appreciated that carbonyl compound can promote the decarboxylation of the amino acid. In this paper, we have performed the experimental and theoretical investigation into the gas-phase decarboxylation of the amino acid anion catalyzed by the aromatic aldehyde via the imine intermediate on the basis of the tandem mass spectrometry (MS/MS) technique and density functional theory (DFT) calculation. The results show that the aromatic aldehyde can achieve a remarkable catalytic effect. Moreover, the catalytic mechanism varies according to the type of amino acid: (i) The decarboxylation of α-amino acid anion is determined by the direct dissociation of the Csbnd C bond adjacent to the carboxylate, for the resulting carbanion can be well stabilized by the conjugation between α-carbon, Cdbnd N bond and benzene ring. (ii) The decarboxylation of non-α-amino acid anion proceeds via a SN2-like transition state, in which the dissociation of the Csbnd C bond adjacent to the carboxylate and attacking of the resulting carbanion to the Cdbnd N bond or benzene ring take place at the same time. Specifically, for β-alanine, the resulting carbanion preferentially attacks the benzene ring leading to the benzene anion, because attacking the Cdbnd N bond in the decarboxylation can produce the unstable three or four-membered ring anion. For the other non-α-amino acid anion, the Cdbnd N bond preferentially participates in the decarboxylation, which leads to the pediocratic nitrogen anion.

  7. 20 CFR 655.11 - Certifying officer review of prevailing wage determinations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... LABOR TEMPORARY EMPLOYMENT OF FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process and... Nursing in the United States (H-2B Workers) § 655.11 Certifying officer review of prevailing wage...

  8. United States Department of State Strategic Plan

    DTIC Science & Technology

    1998-01-01

    employment sources such as temporary hires, family member appointments, telecommuting , part- time and jobsharing arrangements, and contracts...primary responsibility for coordination and oversight with respect to science and technology agreements with foreign governments. GOAL: Stabilize

  9. Study of Nb2O(y) (y = 2-5) anion and neutral clusters using anion photoelectron spectroscopy and density functional theory calculations.

    PubMed

    Mann, Jennifer E; Waller, Sarah E; Rothgeb, David W; Jarrold, Caroline Chick

    2011-09-14

    A study combining anion photoelectron spectroscopy and density functional theory calculations on the transition metal suboxide series, Nb(2)O(y)(-) (y = 2-5), is described. Photoelectron spectra of the clusters are obtained, and Franck-Condon simulations using calculated anion and neutral structures and frequencies are used to evaluate the calculations and assign transitions observed in the spectra. The spectra, several of which exhibit partially resolved vibrational structure, show an increase in electron affinity with increasing cluster oxidation state. Hole-burning experiments suggest that the photoelectron spectra of both Nb(2)O(2)(-) and Nb(2)O(3)(-) have contributions from more than one structural isomer. Reasonable agreement between experiment and computational results is found among all oxides. © 2011 American Institute of Physics

  10. Guanidinium can both Cause and Prevent the Hydrophobic Collapse of Biomacromolecules

    PubMed Central

    2017-01-01

    A combination of Fourier transform infrared and phase transition measurements as well as molecular computer simulations, and thermodynamic modeling were performed to probe the mechanisms by which guanidinium (Gnd+) salts influence the stability of the collapsed versus uncollapsed state of an elastin-like polypeptide (ELP), an uncharged thermoresponsive polymer. We found that the cation’s action was highly dependent upon the counteranion with which it was paired. Specifically, Gnd+ was depleted from the ELP/water interface and was found to stabilize the collapsed state of the macromolecule when paired with well-hydrated anions such as SO42–. Stabilization in this case occurred via an excluded volume (or depletion) effect, whereby SO42– was strongly partitioned away from the ELP/water interface. Intriguingly, at low salt concentrations, Gnd+ was also found to stabilize the collapsed state of the ELP when paired with SCN–, which is a strong binder for the ELP. In this case, the anion and cation were both found to be enriched in the collapsed state of the polymer. The collapsed state was favored because the Gnd+ cross-linked the polymer chains together. Moreover, the anion helped partition Gnd+ to the polymer surface. At higher salt concentrations (>1.5 M), GndSCN switched to stabilizing the uncollapsed state because a sufficient amount of Gnd+ and SCN– partitioned to the polymer surface to prevent cross-linking from occurring. Finally, in a third case, it was found that salts which interacted in an intermediate fashion with the polymer (e.g., GndCl) favored the uncollapsed conformation at all salt concentrations. These results provide a detailed, molecular-level, mechanistic picture of how Gnd+ influences the stability of polypeptides in three distinct physical regimes by varying the anion. It also helps explain the circumstances under which guanidinium salts can act as powerful and versatile protein denaturants. PMID:28054487

  11. Pentacoordinate silicon(IV): cationic, anionic and neutral complexes derived from the reaction of NHC→SiCl4 with highly Lewis acidic (C2F5)2SiH2.

    PubMed

    Böttcher, T; Steinhauer, S; Neumann, B; Stammler, H-G; Röschenthaler, G-V; Hoge, B

    2014-06-14

    Addition of NHC→SiCl4 to the highly Lewis acidic bis(pentafluoroethyl)silane ((C2F5)2SiH2) afforded the salt [(NHC)2SiCl2H][(C2F5)2SiCl3] with pentacoordinate silicon in the cation and the anion. The anion represents the first example of a chlorosilicate structurally characterized in the solid state. In this reaction, the long sought pentacoordinate NHC-adduct of silicochloroform was identified as an intermediate and its crystal structure is presented.

  12. Heavy atom vibrational modes and low-energy vibrational autodetachment in nitromethane anions

    NASA Astrophysics Data System (ADS)

    Thompson, Michael C.; Baraban, Joshua H.; Matthews, Devin A.; Stanton, John F.; Weber, J. Mathias

    2015-06-01

    We report infrared spectra of nitromethane anion, CH3NO2-, in the region 700-2150 cm-1, obtained by Ar predissociation spectroscopy and electron detachment spectroscopy. The data are interpreted in the framework of second-order vibrational perturbation theory based on coupled-cluster electronic structure calculations. The modes in the spectroscopic region studied here are mainly based on vibrations involving the heavier atoms; this work complements earlier studies on nitromethane anion that focused on the CH stretching region of the spectrum. Electron detachment begins at photon energies far below the adiabatic electron affinity due to thermal population of excited vibrational states.

  13. Heavy atom vibrational modes and low-energy vibrational autodetachment in nitromethane anions.

    PubMed

    Thompson, Michael C; Baraban, Joshua H; Matthews, Devin A; Stanton, John F; Weber, J Mathias

    2015-06-21

    We report infrared spectra of nitromethane anion, CH3NO2 (-), in the region 700-2150 cm(-1), obtained by Ar predissociation spectroscopy and electron detachment spectroscopy. The data are interpreted in the framework of second-order vibrational perturbation theory based on coupled-cluster electronic structure calculations. The modes in the spectroscopic region studied here are mainly based on vibrations involving the heavier atoms; this work complements earlier studies on nitromethane anion that focused on the CH stretching region of the spectrum. Electron detachment begins at photon energies far below the adiabatic electron affinity due to thermal population of excited vibrational states.

  14. Photodissociation of nitromethane cluster anions.

    PubMed

    Goebbert, Daniel J; Khuseynov, Dmitry; Sanov, Andrei

    2010-08-28

    Three types of anionic fragments are observed in the photodissociation of nitromethane cluster anions, (CH(3)NO(2))(n)(-), n=1-6, at 355 nm: NO(2)(-)(CH(3)NO(2))(k), (CH(3)NO(2))(k)(-), and OH(-) (k

  15. β-Dicyanovinyl substituted porphyrinogen: synthesis, a reversible sensor for picric acid among explosives and a unique sensor for cyanide and fluoride ions by switching between various porphyrinoid states.

    PubMed

    Chahal, Mandeep K; Sankar, Muniappan

    2017-09-12

    β-Dicyanovinyl substituted porphyrinogen (OxP-MN) was synthesized and utilized as a novel multifunctional sensor for the detection of biologically and environmentally important analytes. OxP-MN (1) acts as a selective and reversible probe for rapid colorimetric detection of picric acid (PA) among other nitroaromatics by switching between two porphyrinoid states. This system displayed a higher β 2 value of 1.7 × 10 8 M -2 and was able to detect PA down to 1.12 ppm (4.99 μM). β-Dicyanovinyl substituted porphyrinogen (OxP-MN) reported here contains a porphyrinogen anion binding site and a dicyanovinyl group as a cyanide-dependent reactive subunit. OxP-MN displayed the first evidence that a β-electron acceptor through a vinyl linker in the case of porphyrinogen results in only an abated shift in the spectrum in contrast to its porphyrin analogues. Porphyrinogen OxP-MN (1) can be switched between a number of porphyrinoid states such as metalloporphodimethene, metalloporphyrin, porphyrinogen, etc. by using CN - , F - and other basic anions. In addition, OxP-MN unveils the unique property of detecting toxic cyanide ions and fluoride ions when "hidden" within a mixture of other anions. Also, OxP-MN behaves as a dual sensor for picric acid and basic anions such as F - , CN - , OAc - , and H 2 PO 4 - via the indicator displacement assay under the unrestricted queue.

  16. Ruthenium(II) 2,2'-bibenzimidazole complex as a second-sphere receptor for anions interaction and colorimeter.

    PubMed

    Cui, Ying; Niu, Yan-Li; Cao, Man-Li; Wang, Ke; Mo, Hao-Jun; Zhong, Yong-Rui; Ye, Bao-Hui

    2008-07-07

    A ruthenium(II) complex [Ru(bpy) 2(H 2bbim)](PF 6) 2 ( 1) as anions receptor has been exploited, where Ru(II)-bpy moiety acts as a chromophore and the H 2bbim ligand as an anion binding site. A systematic study suggests that 1 interacts with the Cl (-), Br (-), I (-), NO 3 (-), HSO 4 (-), and H 2PO 4 (-) anions via the formation of hydrogen bonds. Whereas 1 undergoes a stepwise process with the addition of F (-) and OAc (-) anions: formation of the monodeprotonated complex [Ru(bpy) 2(Hbbim)] with a low anion concentration, followed by the double-deprotonated complex [Ru(bpy) 2(bbim)], in the presence of a high anion concentration. These stepwise processes concomitant with the changes of vivid colors from yellow to orange brown and then to violet can be used for probing the F (-) and OAc (-) anions by naked eye. The deprotonation processes are not only determined by the basicity of the anion but also related to the strength of hydrogen bonding, as well as the stability of the formed compounds. Moreover, a double-deprotonated complex [Ru(bpy) 2(bbim)].CH 3OH.H 2O ( 3) has been synthesized, and the structural changes induced by the deprotonation has also been investigated. In addition, complexes [Ru(bpy) 2(Hbbim)] 2(HOAc) 3Cl 2.12H 2O ( 2), [Ru(bpy) 2(Hbbim)](HCCl 3CO 2)(CCl 3CO 2).2H 2O ( 4), and [Ru(bpy) 2(H 2bbim)](CF 3CO 2) 2.4H 2O ( 5) have been synthesized to observe the second sphere coordination between the Ru(II)-H 2bbim moiety and carboxylate groups via hydrogen bonds in the solid state.

  17. Experimental and theoretical identification of the Fe(vii) oxidation state in FeO4.

    PubMed

    Lu, Jun-Bo; Jian, Jiwen; Huang, Wei; Lin, Hailu; Li, Jun; Zhou, Mingfei

    2016-11-16

    The experimentally known highest oxidation state of iron has been determined to be Fe(vi) so far. Here we report a combined matrix-isolation infrared spectroscopic and theoretical study of two interconvertible iron oxide anions: a dioxoiron peroxide complex [(η 2 -O 2 )FeO 2 ] - with a C 2v -structure and a tetroxide FeO 4 - with a D 2d tetrahedral structure, which are formed by co-condensation of laser-ablated iron atoms and electrons with O 2 /Ar mixtures at 4 K. Quantum chemistry theoretical studies indicate that the Jahn-Teller distorted tetroxide FeO 4 - anion is a d 1 species with hereto the highest iron formal oxidation state Fe(vii).

  18. A One-year Follow-up Study on Predictors of Temporary Leaves and Drop-outs among Students at a Women's Junior College

    PubMed Central

    Murai, Hideko; Nakayama, Takeo

    2008-01-01

    Background In Japan, the temporary leave and drop-out rate of university or junior college students has been increasing in recent years, and many cases have been attributed to psychological problems. To establish a mental health support system for entering students, we conducted a questionnaire and follow-up survey, and explored predictors of temporary leaves and drop-outs among junior college women. Methods Our sample consisted of 485 first-year female students attending a junior college in Osaka, Japan. Between 1998 and 2002, the following factors were assessed: lifestyle, college life, subjective well-being measured by the General Well-Being Schedule (GWBS), self-esteem, and emotional support network. A follow-up survey was conducted during 1 year. Results Thirty-seven women, who had taken temporary leaves or had dropped out during the first year, showed unfavorable responses to lifestyle, college life and/or subjective well-being compared with other students. No differences in self-esteem and emotional support network were found between the two groups. A multiple regression analysis showed that non-existence of interesting club activity, smoking, and low level of life satisfaction and emotional stability measured by the GWBS were predictors of temporary leaves and drop-outs. Conclusion It may be possible to determine which students are at risk for taking temporary leaves or dropping out based on their psychological state and lifestyle at the time of enrollment in college. More support is needed to continue the students at school who are at high risk for taking temporary leaves or dropping out. PMID:18305364

  19. A one-year follow-up study on predictors of temporary leaves and drop-outs among students at a women's junior college.

    PubMed

    Murai, Hideko; Nakayama, Takeo

    2008-01-01

    In Japan, the temporary leave and drop-out rate of university or junior college students has been increasing in recent years, and many cases have been attributed to psychological problems. To establish a mental health support system for entering students, we conducted a questionnaire and follow-up survey, and explored predictors of temporary leaves and drop-outs among junior college women. Our sample consisted of 485 first-year female students attending a junior college in Osaka, Japan. Between 1998 and 2002, the following factors were assessed: lifestyle, college life, subjective well-being measured by the General Well-Being Schedule (GWBS), self-esteem, and emotional support network. A follow-up survey was conducted during 1 year. Thirty-seven women, who had taken temporary leaves or had dropped out during the first year, showed unfavorable responses to lifestyle, college life and/or subjective well-being compared with other students. No differences in self-esteem and emotional support network were found between the two groups. A multiple regression analysis showed that non-existence of interesting club activity, smoking, and low level of life satisfaction and emotional stability measured by the GWBS were predictors of temporary leaves and drop-outs. It may be possible to determine which students are at risk for taking temporary leaves or dropping out based on their psychological state and lifestyle at the time of enrollment in college. More support is needed to continue the students at school who are at high risk for taking temporary leaves or dropping out.

  20. Measuring persistence to hormonal therapy in patients with breast cancer: accounting for temporary treatment discontinuation.

    PubMed

    Huiart, Laetitia; Ferdynus, Cyril; Dell'Aniello, Sophie; Bakiri, Naciba; Giorgi, Roch; Suissa, Samy

    2014-08-01

    Several studies have been conducted to estimate persistence to hormonal therapy among women with breast cancer (BC). Most studies focus on first treatment discontinuation. Patients, however, can have numerous periods of treatment discontinuation or treatment exposure. Our objective is to estimate persistence to tamoxifen in patients with BC while accounting for temporary treatment discontinuations and this by using multi-state (MS) models. A cohort of 10,806 women with BC having received at least one prescription of tamoxifen between 1998 and 2008 was constituted from the UK General Practice Research Database. We fitted a semi-Markov model with three states to estimate the probability of being off treatment over a 5-year period while accounting for temporary treatment discontinuations (transition between on treatment and off treatment) and competing risks (recurrence of BC or death). Non-persistence, as estimated from the MS model, ranged from 12.1% (95% confidence interval [95%CI]: 9.2-15.1) at 1 year to 14.9% (95%CI: 11.7-18.1) at 5 years. Estimations of non-persistence based on the Kaplan-Meier model were higher, i.e., 29.3% (95%CI: 28.1-30.6) at 5 years, as well as those obtained from a competing risk model, i.e., 24.0% (95%CI: 22.9-25.1). Most temporary discontinuations (94.7%) lasted less than 6 months. Temporary treatment discontinuations are frequent and should be accounted for when measuring adherence to treatment. MS models can provide a useful framework for this sort of analysis insofar as they help describe patients' complex behavior. This may help tailor interventions that improve persistence to hormonal therapy among women with BC. Copyright © 2014 John Wiley & Sons, Ltd.

  1. A Model for Negative Ion Chemistry in Titan’s Ionosphere

    NASA Astrophysics Data System (ADS)

    Mukundan, Vrinda; Bhardwaj, Anil

    2018-04-01

    We developed a one-dimensional photochemical model for the dayside ionosphere of Titan for calculating the density profiles of negative ions under steady-state photochemical equilibrium condition. We concentrated on the T40 flyby of the Cassini orbiter and used the in situ measurements from instruments on board Cassini as input to the model. Using the latest available reaction rate coefficients and dissociative electron attachment cross sections, the densities of 10 anions are calculated. Our study shows CN‑ as the dominant anion, followed by C3N‑, which agrees with the results of previous calculations. We suggest that H‑ could be an important anion in Titan’s ionosphere and is the second most abundant anion at altitudes greater than 1200 km. The main production channel of the major ion CN‑ is the reaction of H‑ with HCN. The H‑ also play a major role in the production of anions C2H‑, C6H‑, and OH‑. We present a comparison of the calculated ion density profiles with the relative density profiles derived using recently reported Cassini CAPS/ELS observations.

  2. ESIPT and photodissociation of 3-hydroxychromone in solution: photoinduced processes studied by static and time-resolved UV/Vis, fluorescence, and IR spectroscopy.

    PubMed

    Chevalier, Katharina; Grün, Anneken; Stamm, Anke; Schmitt, Yvonne; Gerhards, Markus; Diller, Rolf

    2013-11-07

    The spectral properties of fluorescence sensors such as 3-hydroxychromone (3-HC) and its derivatives are sensitive to interaction with the surrounding medium as well as to substitution. 3-HC is a prototype system for other derivatives because it is the basic unit of all flavonoides undergoing ESIPT and is not perturbed by a substituent. In this study, the elementary processes and intermediate states in the photocycle of 3-HC as well as its anion were identified and characterized by the use of static and femtosecond time-resolved spectroscopy in different solvents (methylcyclohexane, acetonitrile, ethanol, and water at different pH). Electronic absorption and fluorescence spectra and lifetimes of the intermediate states were obtained for the normal, tautomer and anionic excited state, while mid-IR vibrational spectra yielded structural information on ground and excited states of 3-HC. A high sensitivity on hydrogen-bonding perturbations was observed, leading to photoinduced anion formation in water, while in organic solvents, different processes are suggested, including slow picosecond ESIPT and contribution of the trans-structure excited state or a different stable solvation state with different direction of OH. The formation of the latter could be favored by the lack of a substituent increasing contact points for specific solute-solvent interactions at the hydroxyl group compared to substituted derivatives. The effect of substituents has to be considered for the design of future fluorescence sensors based on 3-HC.

  3. New chemistry of transition metal oxyhydrides

    PubMed Central

    Kobayashi, Yoji; Hernandez, Olivier; Tassel, Cédric; Kageyama, Hiroshi

    2017-01-01

    Abstract In this review we describe recent advances in transition metal oxyhydride chemistry obtained by topochemical routes, such as low temperature reduction with metal hydrides, or high-pressure solid-state reactions. Besides the crystal chemistry, magnetic and transport properties of the bulk powder and epitaxial thin film samples, the remarkable lability of the hydride anion is particularly highlighted as a new strategy to discover unprecedented mixed anion materials. PMID:29383042

  4. High cation transport polymer electrolyte

    DOEpatents

    Gerald, II, Rex E.; Rathke, Jerome W [Homer Glen, IL; Klingler, Robert J [Westmont, IL

    2007-06-05

    A solid state ion conducting electrolyte and a battery incorporating same. The electrolyte includes a polymer matrix with an alkali metal salt dissolved therein, the salt having an anion with a long or branched chain having not less than 5 carbon or silicon atoms therein. The polymer is preferably a polyether and the salt anion is preferably an alkyl or silyl moiety of from 5 to about 150 carbon/silicon atoms.

  5. Synthesis, structures, and properties of crystalline salts with radical anions of metal-containing and metal-free phthalocyanines.

    PubMed

    Konarev, Dmitri V; Kuzmin, Alexey V; Faraonov, Maxim A; Ishikawa, Manabu; Khasanov, Salavat S; Nakano, Yoshiaki; Otsuka, Akihiro; Yamochi, Hideki; Saito, Gunzi; Lyubovskaya, Rimma N

    2015-01-12

    Radical anion salts of metal-containing and metal-free phthalocyanines [MPc(3-)](·-), where M = Cu(II), Ni(II), H2, Sn(II), Pb(II), Ti(IV)O, and V(IV)O (1-10) with tetraalkylammonium cations have been obtained as single crystals by phthalocyanine reduction with sodium fluorenone ketyl. Their formation is accompanied by the Pc ligand reduction and affects the molecular structure of metal phthalocyanine radical anions as well as their optical and magnetic properties. Radical anions are characterized by the alternation of short and long C-Nimine bonds in the Pc ligand owing to the disruption of its aromaticity. Salts 1-10 show new bands at 833-1041 nm in the NIR range, whereas the Q- and Soret bands are blue-shifted by 0.13-0.25 eV (38-92 nm) and 0.04-0.07 eV (4-13 nm), respectively. Radical anions with Ni(II), Sn(II), Pb(II), and Ti(IV)O have S = 1/2 spin state, whereas [Cu(II)Pc(3-)](·-) and [V(IV)OPc(3-)](·-) containing paramagnetic Cu(II) and V(IV)O have two S = 1/2 spins per radical anion. Central metal atoms strongly affect EPR spectra of phthalocyanine radical anions. Instead of narrow EPR signals characteristic of metal-free phthalocyanine radical anions [H2Pc(3-)](·-) (linewidth of 0.08-0.24 mT), broad EPR signals are manifested (linewidth of 2-70 mT) with g-factors and linewidths that are strongly temperature-dependent. Salt 11 containing the [Na(I)Pc(2-)](-) anions as well as previously studied [Fe(I)Pc(2-)](-) and [Co(I)Pc(2-)](-) anions that are formed without reduction of the Pc ligand do not show changes in molecular structure or optical and magnetic properties characteristic of [MPc(3-)](·-) in 1-10. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Multi-State Fuel Waiver

    EPA Pesticide Factsheets

    September 2016 temporary Fuel Waiver Concerning Alabama, Delaware, Georgia, Kentucky, Maryland, Mississippi, New Jersey, North Carolina, South Carolina, Tennessee, Virginia and the District of Columbia

  7. Detection and Quantification of Inorganic and Organic Anions in Natural, Potable, and Wastewaters in Northern New York Using Capillary Zone Electrophoresis and Indirect UV Detection

    PubMed Central

    Varden, Lara; Smith, Britannia; Bou-Abdallah, Fadi

    2017-01-01

    Capillary zone electrophoresis (CZE) is a sensitive and rapid technique used for determining traces of inorganic and organic anions in potable, natural, and wastewaters. Here, CZE with indirect UV-diode array detection (CZE-DAD) was employed with a background electrolyte system comprising of an Agilent Technologies proprietary basic anion buffer at pH 12.0 and a forensic anion detection method. The limits of detection (LOD) for this method ranged between 3 and 5 ppm and involved hydrodynamic injection of 50 mbar for 6 s with a negative polarity separation voltage of −30 kV at 30°C, a detection wavelength of 350 nm and indirect reference of 275 nm. Fourteen different anions were checked for in the water samples that were examined and included bromide, chloride, thiosulfate, nitrate, nitrite, sulfate, azide, carbonate, fluoride, arsenate, phosphate, acetate, lactate, and silicate. The water samples were collected from Northern New York towns and the Raquette River water system, the third longest river in New York State and the largest watershed of the central and western Adirondacks. The concentrations detected for these anions ranged from <5.0 ppm to 260 ppm. PMID:29057145

  8. A novel quasi-solid state electrolyte with highly effective polysulfide diffusion inhibition for lithium-sulfur batteries

    PubMed Central

    Zhong, Hai; Wang, Chunhua; Xu, Zhibin; Ding, Fei; Liu, Xinjiang

    2016-01-01

    Polymer solid state electrolytes are actively sought for their potential application in energy storage devices, particularly lithium metal rechargeable batteries. Herein, we report a polymer with high concentration salts as a quasi-solid state electrolyte used for lithium-sulfur cells, which shows an ionic conductivity of 1.6 mS cm−1 at room temperature. The cycling performance of Li-S battery with this electrolyte shows a long cycle life (300 cycles) and high coulombic efficiency (>98%), without any consuming additives in the electrolyte. Moreover, it also shows a remarkably decreased self-discharge (only 0.2%) after storage for two weeks at room temperature. The reason can be attributed to that the electrolyte can suppress polysulfide anions diffusion, due to the high ratio oxygen atoms with negative charges which induce an electrical repulsion to the polysulfide anions, and their relatively long chains which can provide additional steric hindrance. Thus, the polysulfide anions can be located around carbon particles, which result in remarkably improved overall electrochemical performance, and also the electrolyte have a function of suppress the formation of lithium dendrites on the lithium anode surface. PMID:27146645

  9. Absorption and luminescence spectroscopy of mass-selected flavin adenine dinucleotide mono-anions

    NASA Astrophysics Data System (ADS)

    Giacomozzi, L.; Kjær, C.; Langeland Knudsen, J.; Andersen, L. H.; Brøndsted Nielsen, S.; Stockett, M. H.

    2018-06-01

    We report the absorption profile of isolated Flavin Adenine Dinucleotide (FAD) mono-anions recorded using photo-induced dissociation action spectroscopy. In this charge state, one of the phosphoric acid groups is deprotonated and the chromophore itself is in its neutral oxidized state. These measurements cover the first four optical transitions of FAD with excitation energies from 2.3 to 6.0 eV (210-550 nm). The S0 → S2 transition is strongly blue shifted relative to aqueous solution, supporting the view that this transition has a significant charge-transfer character. The remaining bands are close to their solution-phase positions. This confirms that the large discrepancy between quantum chemical calculations of vertical transition energies and solution-phase band maxima cannot be explained by solvent effects. We also report the luminescence spectrum of FAD mono-anions in vacuo. The gas-phase Stokes shift for S1 is 3000 cm-1, which is considerably larger than any previously reported for other molecular ions and consistent with a significant displacement of the ground and excited state potential energy surfaces. Consideration of the vibronic structure is thus essential for simulating the absorption and luminescence spectra of flavins.

  10. Probing microhydration effect on the electronic structure of the GFP chromophore anion. Photoelectron spectroscopy and theoretical investigations

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bhaskaran-Nair, Kiran; Valiev, Marat; Deng, Shihu

    2015-12-14

    The photophysics of Green Fluorescent Protein (GFP) chromophore is critically dependent on its local structure and on its environment. Despite extensive experimental and computational studies, there remain many open questions regarding the key fundamental variables that govern this process. One outstanding problem is the role of autoionization as a possible relaxation pathway of the excited state under different environmental conditions. This issue is considered in our work through combined experimental and theoretical studies of microsolvated clusters of the deprotonated p-hydroxybenzylidene-2,3-dimethylimidazolinone anion (HBDI⁻), an analog of GFP chromophore. Through selective generation of microsolvated structures of predetermined size and subsequent analysis ofmore » experimental photoelectron spectra by high level ab-initio methods we are able to precisely identify the structure of the system, establish the accuracy of theoretical data, and provide reliable description of auto-ionization process as a function of hydrogen-bonding environment. Our study clearly illustrates the first few water molecules progressively stabilize the excited state of the chromophore anion against the autodetached neutral state, which should be an important trait for crystallographic water molecules in GFPs that has not been fully explored to date.« less

  11. Probing microhydration effect on the electronic structure of the GFP chromophore anion: Photoelectron spectroscopy and theoretical investigations

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bhaskaran-Nair, Kiran; Shelton, William A.; Center for Computation and Technology, Louisiana State University, Baton Rouge, Louisiana 70803

    2015-12-14

    The photophysics of the Green Fluorescent Protein (GFP) chromophore is critically dependent on its local structure and on its environment. Despite extensive experimental and computational studies, there remain many open questions regarding the key fundamental variables that govern this process. One outstanding problem is the role of autoionization as a possible relaxation pathway of the excited state under different environmental conditions. This issue is considered in our work through combined experimental and theoretical studies of microsolvated clusters of the deprotonated p-hydroxybenzylidene-2,3-dimethylimidazolinone anion (HBDI{sup −}), an analog of the GFP chromophore. Through selective generation of microsolvated structures of predetermined size andmore » subsequent analysis of experimental photoelectron spectra by high level ab initio methods, we are able to precisely identify the structure of the system, establish the accuracy of theoretical data, and provide reliable description of auto-ionization process as a function of hydrogen-bonding environment. Our study clearly illustrates the first few water molecules progressively stabilize the excited state of the chromophore anion against the autodetached neutral state, which should be an important trait for crystallographic water molecules in GFPs that has not been fully explored to date.« less

  12. Direct NMR Evidence that Transient Tautomeric and Anionic States in dG·dT Form Watson-Crick-like Base Pairs.

    PubMed

    Szymanski, Eric S; Kimsey, Isaac J; Al-Hashimi, Hashim M

    2017-03-29

    The replicative and translational machinery utilizes the unique geometry of canonical G·C and A·T/U Watson-Crick base pairs to discriminate against DNA and RNA mismatches in order to ensure high fidelity replication, transcription, and translation. There is growing evidence that spontaneous errors occur when mismatches adopt a Watson-Crick-like geometry through tautomerization and/or ionization of the bases. Studies employing NMR relaxation dispersion recently showed that wobble dG·dT and rG·rU mismatches in DNA and RNA duplexes transiently form tautomeric and anionic species with probabilities (≈0.01-0.40%) that are in concordance with replicative and translational errors. Although computational studies indicate that these exceptionally short-lived and low-abundance species form Watson-Crick-like base pairs, their conformation could not be directly deduced from the experimental data, and alternative pairing geometries could not be ruled out. Here, we report direct NMR evidence that the transient tautomeric and anionic species form hydrogen-bonded Watson-Crick-like base pairs. A guanine-to-inosine substitution, which selectively knocks out a Watson-Crick-type (G)N2H 2 ···O2(T) hydrogen bond, significantly destabilized the transient tautomeric and anionic species, as assessed by lack of any detectable chemical exchange by imino nitrogen rotating frame spin relaxation (R 1ρ ) experiments. An 15 N R 1ρ NMR experiment targeting the amino nitrogen of guanine (dG-N2) provides direct evidence for Watson-Crick (G)N2H 2 ···O2(T) hydrogen bonding in the transient tautomeric state. The strategy presented in this work can be generally applied to examine hydrogen-bonding patterns in nucleic acid transient states including in other tautomeric and anionic species that are postulated to play roles in replication and translational errors.

  13. Diagnostic cyclisation reactions which follow phosphate transfer to carboxylate anion centres for energised [M-H]- anions of pTyr-containing peptides.

    PubMed

    Tran, T T Nha; Wang, Tianfang; Hack, Sandra; Bowie, John H

    2011-09-15

    The low-energy negative ion phosphoTyr to C-terminal -CO(2)PO(3)H(2) rearrangement occurs for energised peptide [M-H](-) anions even when there are seven amino acid residues between the pTyr and C-terminal amino acid residues. The rearranged C-terminal -CO(2)PO(2)H(O(-)) group effects characteristic S(N)i cyclisation/cleavage reactions. The most pronounced of these involves the electrophilic central backbone carbon of the penultimate amino acid residue. This reaction is aided by the intermediacy of an H-bonded intermediate in which the nucleophilic and electrophilic reaction centres are held in proximity in order for the S(N)i cyclisation/cleavage to proceed. The ΔG(reaction) is +184 kJ mol(-1) with the barrier to the S(N)i transition state being +240 kJ mol(-1) at the HF/6-31 + G(d)//AM1 level of theory. A similar phosphate rearrangement from pTyr to side chain CO(2)(-) (of Asp or Glu) may also occur for energised peptide [M-H](-) anions. The reaction is favourable: ΔG(reaction) is -44 kJ mol(-1) with a maximum barrier of +21 kJ mol(-1) (to the initial transition state) when Asp and Tyr are adjacent. The rearranged species R(1)-Tyr-NHCH(CH(2)CO(2)PO(3)H(-))COR(2) (R(1)  = CHO; R(2)  = OCH(3)) may undergo an S(N)i six-centred cyclisation/cleavage reaction to form the product anion R(1)-Tyr(NH(-)). This process has a high energy requirement [ΔG(reaction)  = +224 kJ mol(-1), with the barrier to the S(N)i transition state being +299 kJ mol(-1)]. Copyright © 2011 John Wiley & Sons, Ltd.

  14. Selection Rule of Preferred Doping Site for n-Type Oxides

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Li, C.; Li, J.; Li, S. S.

    2012-06-25

    Using first-principles calculations and analysis, we show that to create shallow n-type dopants in oxides, anion site doping is preferred for more covalent oxides such as SnO{sub 2} and cation site doping is preferred for more ionic oxides such as ZnO. This is because for more ionic oxides, the conduction band minimum (CBM) state actually contains a considerable amount of O 3s orbitals, thus anion site doping can cause large perturbation on the CBM and consequently produces deeper donor levels. We also show that whether it is cation site doping or anion site doping, the oxygen-poor condition should always bemore » used.« less

  15. Heavy atom vibrational modes and low-energy vibrational autodetachment in nitromethane anions

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Thompson, Michael C.; Weber, J. Mathias, E-mail: weberjm@jila.colorado.edu; Department of Chemistry and Biochemistry, University of Colorado at Boulder, 215UCB, Boulder, Colorado 80309-0215

    2015-06-21

    We report infrared spectra of nitromethane anion, CH{sub 3}NO{sub 2}{sup −}, in the region 700–2150 cm{sup −1}, obtained by Ar predissociation spectroscopy and electron detachment spectroscopy. The data are interpreted in the framework of second-order vibrational perturbation theory based on coupled-cluster electronic structure calculations. The modes in the spectroscopic region studied here are mainly based on vibrations involving the heavier atoms; this work complements earlier studies on nitromethane anion that focused on the CH stretching region of the spectrum. Electron detachment begins at photon energies far below the adiabatic electron affinity due to thermal population of excited vibrational states.

  16. The chemistry of gold as an anion.

    PubMed

    Jansen, Martin

    2008-09-01

    Due to relativistic and classical shell structure effects, the 6s orbital of gold is significantly contracted and energetically stabilized. This is reflected by a strikingly high electron affinity, and a distinct tendency to adopt negatively polarized valence states. This tutorial review focuses on the chemistry of gold as an anion, displaying the integral ionic charge number of 1-. Two synthetic approaches to compounds containing monoatomic gold anions have become available: (1) reacting elemental gold with molten caesium and an oxide, e.g. Cs2O; (2) metathesis reactions involving Au- dissolved in liquid ammonia. Both procedures have proven to be rather versatile. Aurides synthesized along these routes are surveyed, in particular with respect to their structures and bonding properties.

  17. The selectivity of water-based pyrophosphate recognition is tuned by metal substitution in dimetallic receptors.

    PubMed

    Svane, Simon; Kjeldsen, Frank; McKee, Vickie; McKenzie, Christine J

    2015-07-14

    The three dimetallic compounds [Ga2(bpbp)(OH)2(H2O)2](ClO4)3, [In2(bpbp)(CH3CO2)2](ClO4)3 and [Zn2(bpbp)(HCO2)2](ClO4) (bpbp(-) = 2,6-bis((N,N'-bis(2-picolyl)amino)methyl)-4-tertbutylphenolate) were evaluated as stable solid state precursors for reactive solution state receptors to use for the recognition of the biologically important anion pyrophosphate in water at neutral pH. Indicator displacement assays using in situ generated complex-pyrocatechol violet adducts, {M2(bpbp)(HxPV)}(n+) M = Ga(3+), In(3+), Zn(2+), were tested for selectivity in their reactions with a series of common anions: pyrophosphate, phosphate, ATP, arsenate, nitrate, perchlorate, chloride, sulfate, formate, carbonate and acetate. The receptor employing Ga(3+) showed a slow but visually detectable response (blue to yellow) in the presence of one equivalent of pyrophosphate but no response to any other anion, even when they were present in much higher concentrations. The systems based on In(3+) or Zn(2+) show less selectivity in accord with visibly discernible responses to several of the anions. These results demonstrate a facile method for increasing anion selectivity without modification of an organic dinucleating ligand scaffold. The comfortable supramolecular recognition of pyrophosphate by the dimetallic complexes is demonstrated by the single crystal X-ray structure of [Ga2(bpbp)(HP2O7)](ClO4)2 in which the pyrophosphate is coordinated to the two gallium ions via four of its oxygen atoms.

  18. Formation of Anionic C, N-bearing Chains in the Interstellar Medium via Reactions of H- with HC x N for Odd-valued x from 1 to 7

    NASA Astrophysics Data System (ADS)

    Gianturco, F. A.; Satta, M.; Yurtsever, E.; Wester, R.

    2017-11-01

    We investigate the relative efficiencies of low-temperature chemical reactions in the interstellar medium with H- anion reacting in the gas phase with cyanopolyyne neutral molecules, leading to the formation of anionic {{{C}}}x{{{N}}}- linear chains of different lengths and of H2. All the reactions turn out to be without barriers, highly exothermic reactions that provide a chemical route to the formation of anionic chains of the same length. Some of the anions have been observed in the dark molecular clouds and in the diffuse interstellar envelopes. Quantum calculations are carried out for the corresponding reactive potential energy surfaces for all the odd-numbered members of the series (x = 1, 3, 5, 7). We employ the minimum energy paths to obtain the relevant transition state configurations and use the latter within the variational transition state model to obtain the chemical rates. The present results indicate that at typical temperatures around 100 K, a set of significantly larger rate values exists for x = 3 and x = 5, while the rate values are smaller for CN- and {{{C}}}7{{{N}}}-. At those temperatures, however, all the rates turn out to be larger than the estimates in the current literature for the radiative electron attachment (REA) rates, thus indicating the greater importance of the present chemical path with respect to REA processes at those temperatures. The physical reasons for our findings are discussed in detail and linked with the existing observational findings.

  19. Properties of iron sulfide, hydrosulfide, and mixed sulfide/hydrosulfide cluster anions through photoelectron spectroscopy and density functional theory calculations.

    PubMed

    Yin, Shi; Bernstein, Elliot R

    2016-10-21

    A new magnetic-bottle time-of-flight photoelectron spectroscopy (PES) apparatus is constructed in our laboratory. The PES spectra of iron sulfide, hydrosulfide, and mixed sulfide/hydrosulfide [FeS m (SH) n - ; m, n = 0-3, 0 < (m + n) ≤ 3] cluster anions, obtained at 2.331 eV (532 nm) and 3.492 eV (355 nm) photon energies, are reported. The electronic structure and bonding properties of these clusters are additionally investigated at different levels of density functional theory. The most probable structures and ground state spin multiplicity for these cluster anions are tentatively assigned by comparing their theoretical first vertical detachment energies (VDEs) with their respective experiment values. The behavior of S and (SH) as ligands in these iron sulfide, hydrosulfide, and mixed sulfide/hydrosulfide cluster anions is investigated and compared. The experimental first VDEs for Fe(SH) 1-3 - cluster anions are lower than those found for their respective FeS 1-3 - cluster anions. The experimental first VDEs for FeS 1-3 - clusters are observed to increase for the first two S atoms bound to Fe - ; however, due to the formation of an S-S bond for the FeS 3 - cluster, its first VDE is found to be ∼0.41 eV lower than the first VDE for the FeS 2 - cluster. The first VDEs of Fe(SH) 1-3 - cluster anions are observed to increase with the increasing numbers of SH groups. The calculated partial charges of the Fe atom for ground state FeS 1-3 - and Fe(SH) 1-3 - clusters are apparently related to and correlated with their determined first VDEs. The higher first VDE is correlated with a higher, more positive partial charge for the Fe atom of these cluster anions. Iron sulfide/hydrosulfide mixed cluster anions are also explored in this work: the first VDE for FeS(SH) - is lower than that for FeS 2 - , but higher than that for Fe(SH) 2 - ; the first VDEs for FeS 2 (SH) - and FeS(SH) 2 - are close to that for FeS 3 - , but higher than that for Fe(SH) 3 - . The first VDEs of general iron sulfide, hydrosulfide, and mixed sulfide/hydrosulfide clusters [FeS m (SH) n - ; m, n = 0-3, 0 < (m + n) ≤ 3] are dependent on three properties of these anions: 1. the partial charge on the Fe atom, 2. disulfide bond formation (S-S) in the cluster, and 3. the number of hydrosulfide ligands in the cluster. The higher the partial charge on the Fe atom of these clusters, the larger the first VDE; however, cluster S-S bonding and more (SH) ligands in the cluster lower the cluster anion first VDE.

  20. Properties of iron sulfide, hydrosulfide, and mixed sulfide/hydrosulfide cluster anions through photoelectron spectroscopy and density functional theory calculations

    NASA Astrophysics Data System (ADS)

    Yin, Shi; Bernstein, Elliot R.

    2016-10-01

    A new magnetic-bottle time-of-flight photoelectron spectroscopy (PES) apparatus is constructed in our laboratory. The PES spectra of iron sulfide, hydrosulfide, and mixed sulfide/hydrosulfide [FeSm(SH)n-; m, n = 0-3, 0 < (m + n) ≤ 3] cluster anions, obtained at 2.331 eV (532 nm) and 3.492 eV (355 nm) photon energies, are reported. The electronic structure and bonding properties of these clusters are additionally investigated at different levels of density functional theory. The most probable structures and ground state spin multiplicity for these cluster anions are tentatively assigned by comparing their theoretical first vertical detachment energies (VDEs) with their respective experiment values. The behavior of S and (SH) as ligands in these iron sulfide, hydrosulfide, and mixed sulfide/hydrosulfide cluster anions is investigated and compared. The experimental first VDEs for Fe(SH)1-3- cluster anions are lower than those found for their respective FeS1-3- cluster anions. The experimental first VDEs for FeS1-3- clusters are observed to increase for the first two S atoms bound to Fe-; however, due to the formation of an S-S bond for the FeS3- cluster, its first VDE is found to be ˜0.41 eV lower than the first VDE for the FeS2- cluster. The first VDEs of Fe(SH)1-3- cluster anions are observed to increase with the increasing numbers of SH groups. The calculated partial charges of the Fe atom for ground state FeS1-3- and Fe(SH)1-3- clusters are apparently related to and correlated with their determined first VDEs. The higher first VDE is correlated with a higher, more positive partial charge for the Fe atom of these cluster anions. Iron sulfide/hydrosulfide mixed cluster anions are also explored in this work: the first VDE for FeS(SH)- is lower than that for FeS2-, but higher than that for Fe(SH)2-; the first VDEs for FeS2(SH)- and FeS(SH)2- are close to that for FeS3-, but higher than that for Fe(SH)3-. The first VDEs of general iron sulfide, hydrosulfide, and mixed sulfide/hydrosulfide clusters [FeSm(SH)n-; m, n = 0-3, 0 < (m + n) ≤ 3] are dependent on three properties of these anions: 1. the partial charge on the Fe atom, 2. disulfide bond formation (S-S) in the cluster, and 3. the number of hydrosulfide ligands in the cluster. The higher the partial charge on the Fe atom of these clusters, the larger the first VDE; however, cluster S-S bonding and more (SH) ligands in the cluster lower the cluster anion first VDE.

  1. 77 FR 16974 - Special Local Regulations; Ocean State Tall Ships Festival 2012, Narragansett Bay, RI

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-23

    ...-AA08 Special Local Regulations; Ocean State Tall Ships Festival 2012, Narragansett Bay, RI AGENCY... Island, for the Ocean State Tall Ships Festival 2012. This action is necessary to provide for the safety..., during the Ocean State Tall Ships Festival on July 6-9, 2012. These temporary special local regulations...

  2. 14 CFR 91.138 - Temporary flight restrictions in national disaster areas in the State of Hawaii.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... disaster areas in the State of Hawaii. 91.138 Section 91.138 Aeronautics and Space FEDERAL AVIATION... areas in the State of Hawaii. (a) When the Administrator has determined, pursuant to a request and justification provided by the Governor of the State of Hawaii, or the Governor's designee, that an inhabited...

  3. The mechanism of water/ion exchange at a protein surface: a weakly bound chloride in Helicobacter pylori apoflavodoxin.

    PubMed

    Galano-Frutos, Juan J; Morón, M Carmen; Sancho, Javier

    2015-11-21

    Binding/unbinding of small ligands, such as ions, to/from proteins influences biochemical processes such as protein folding, enzyme catalysis or protein/ligand recognition. We have investigated the mechanism of chloride/water exchange at a protein surface (that of the apoflavodoxin from Helicobacter pylori) using classical all-atom molecular dynamics simulations. They reveal a variety of chloride exit routes and residence times; the latter is related to specific coordination modes of the anion. The role of solvent molecules in the mechanism of chloride unbinding has been studied in detail. We see no temporary increase in chloride coordination along the release process. Instead, the coordination of new water molecules takes place in most cases after the chloride/protein atom release event has begun. Moreover, the distribution function of water entrance events into the first chloride solvation shell peaks after chloride protein atom dissociation events. All these observations together seem to indicate that water molecules simply fill the vacancies left by the previously coordinating protein residues. We thus propose a step-by-step dissociation pathway in which protein/chloride interactions gradually break down before new water molecules progressively fill the vacant positions left by protein atoms. As observed for other systems, water molecules associated with bound chloride or with protein atoms have longer residence times than those bound to the free anion. The implications of the exchange mechanism proposed for the binding of the FMN (Flavin Mononucleotide) protein cofactor are discussed.

  4. Federal employees health benefits program modification of eligibility to certain employees on temporary appointments and certain employees on seasonal and intermittent schedules. Final rule.

    PubMed

    2014-10-17

    The United States Office of Personnel Management (OPM) is issuing a final rule to modify eligibility for enrollment under the Federal Employees Health Benefits (FEHB) Program to certain temporary, seasonal, and intermittent employees who are identified as full-time employees. This final rule follows a notice of proposed rulemaking published July 29, 2014. This regulation will allow newly eligible Federal employees to enroll no later than January 2015.

  5. Validating alternative methodologies to estimate the hydrological regime of temporary streams when flow data are unavailable

    NASA Astrophysics Data System (ADS)

    Llorens, Pilar; Gallart, Francesc; Latron, Jérôme; Cid, Núria; Rieradevall, Maria; Prat, Narcís

    2016-04-01

    Aquatic life in temporary streams is strongly conditioned by the temporal variability of the hydrological conditions that control the occurrence and connectivity of diverse mesohabitats. In this context, the software TREHS (Temporary Rivers' Ecological and Hydrological Status) has been developed, in the framework of the LIFE Trivers project, to help managers for adequately implement the Water Framework Directive in this type of water bodies. TREHS, using the methodology described in Gallart et al (2012), defines six temporal 'aquatic states', based on the hydrological conditions representing different mesohabitats, for a given reach at a particular moment. Nevertheless, hydrological data for assessing the regime of temporary streams are often non-existent or scarce. The scarcity of flow data makes frequently impossible the characterization of temporary streams hydrological regimes and, as a consequence, the selection of the correct periods and methods to determine their ecological status. Because of its qualitative nature, the TREHS approach allows the use of alternative methodologies to assess the regime of temporary streams in the lack of observed flow data. However, to adapt the TREHS to this qualitative data both the temporal scheme (from monthly to seasonal) as well as the number of aquatic states (from 6 to 3) have been modified. Two alternatives complementary methodologies were tested within the TREHS framework to assess the regime of temporary streams: interviews and aerial photographs. All the gauging stations (13) belonging to the Catalan Internal Catchments (NE, Spain) with recurrent zero flows periods were selected to validate both methodologies. On one hand, non-structured interviews were carried out to inhabitants of villages and small towns near the gauging stations. Flow permanence metrics for input into TREHS were drawn from the notes taken during the interviews. On the other hand, the historical series of available aerial photographs (typically 10) were examined. In this case, flow permanence metrics were estimated as the proportion of photographs presenting stream flow. Results indicate that for streams being more than 25% of the time dry, interviews systematically underestimated flow, but the qualitative information given by inhabitants was of great interest to understand river dynamics. On the other hand, the use of aerial photographs gave a good estimation of flow permanence, but the seasonality was conditioned to the capture date of the aerial photographs. For these reasons, we recommend to use both methodologies together.

  6. Activator anion binding site in pyridoxal phosphorylase b: the binding of phosphite, phosphate, and fluorophosphate in the crystal.

    PubMed Central

    Oikonomakos, N. G.; Zographos, S. E.; Tsitsanou, K. E.; Johnson, L. N.; Acharya, K. R.

    1996-01-01

    It has been established that phosphate analogues can activate glycogen phosphorylase reconstituted with pyridoxal in place of the natural cofactor pyridoxal 5'-phosphate (Change YC. McCalmont T, Graves DJ. 1983. Biochemistry 22:4987-4993). Pyridoxal phosphorylase b has been studied by kinetic, ultracentrifugation, and X-ray crystallographic experiments. In solution, the catalytically active species of pyridoxal phosphorylase b adopts a conformation that is more R-state-like than that of native phosphorylase b, but an inactive dimeric species of the enzyme can be stabilized by activator phosphite in combination with the T-state inhibitor glucose. Co-crystals of pyridoxal phosphorylase b complexed with either phosphite, phosphate, or fluorophosphate, the inhibitor glucose, and the weak activator IMP were grown in space group P4(3)2(1)2, with native-like unit cell dimensions, and the structures of the complexes have been refined to give crystallographic R factors of 18.5-19.2%, for data between 8 and 2.4 A resolution. The anions bind tightly at the catalytic site in a similar but not identical position to that occupied by the cofactor 5'-phosphate group in the native enzyme (phosphorus to phosphorus atoms distance = 1.2 A). The structural results show that the structures of the pyridoxal phosphorylase b-anion-glucose-IMP complexes are overall similar to the glucose complex of native T-state phosphorylase b. Structural comparisons suggest that the bound anions, in the position observed in the crystal, might have a structural role for effective catalysis. PMID:8976550

  7. Texas Red transport across rat and dogfish shark (Squalus acanthias) choroid plexus.

    PubMed

    Reichel, Valeska; Miller, David S; Fricker, Gert

    2008-10-01

    Confocal microscopy and image analysis were used to compare driving forces, specificity, and regulation of transport of the fluorescent organic anion, Texas Red (sulforhodamine 101 free acid; TR), in lateral choroid plexus (CP) isolated from rat and an evolutionarily ancient vertebrate, dogfish shark (Squalus acanthias). CP from both species exhibited concentrative, specific, and metabolism-dependent TR transport from bath to subepithelial/vascular space; at steady state, TR accumulation in vascular/subepithelial space was substantially higher than in epithelial cells. In rat CP, steady-state TR accumulation in subepithelial/vascular spaces was reduced by Na(+)-replacement, but was not affected by a 10-fold increase in buffer K(+). In shark CP, Na(+)-replacement did not alter TR accumulation in either tissue compartment; subepithelial/vascular space levels of TR were reduced in high-K(+) medium. In both species, steady-state TR accumulation was not affected by p-aminohippurate or leukotriene C4, suggesting that neither organic anion transporters (SLC22A family) nor multidrug resistance-associated proteins (ABCC family) contributed. In rat CP, digoxin was without effect, indicating that organic anion transporting polypeptide isoform 2 was not involved. Several organic anions reduced cellular and subepithelial/vascular space TR accumulation in both tissues, including estrone sulfate, taurocholate, and the Mrp1 inhibitor MK571. In rat CP, TR accumulation in subepithelial/vascular spaces increased with PKA activation (forskolin), but was not affected by PKC activation (phorbol ester). In shark, neither PKA nor PKC activation specifically affected TR transport. Thus, rat and dogfish shark CP transport TR but do so using different basic mechanisms that respond to different regulatory signals.

  8. Kinetic Analysis for Macrocyclizations Involving Anionic Template at the Transition State

    PubMed Central

    Martí-Centelles, Vicente; Burguete, M. Isabel; Luis, Santiago V.

    2012-01-01

    Several kinetic models for the macrocyclization of a C2 pseudopeptide with a dihalide through a SN2 reaction have been developed. These models not only focus on the kinetic analysis of the main macrocyclization reaction, but also consider the competitive oligomerization/polymerization processes yielding undesired oligomeric/polymeric byproducts. The effect of anions has also been included in the kinetic models, as they can act as catalytic templates in the transition state reducing and stabilizing the transition state. The corresponding differential equation systems for each kinetic model can be solved numerically. Through a comprehensive analysis of these results, it is possible to obtain a better understanding of the different parameters that are involved in the macrocyclization reaction mechanism and to develop strategies for the optimization of the desired processes. PMID:22666148

  9. Fibre reinforcement of two temporary composite bridge materials--effect upon flexural properties.

    PubMed

    Al Twal, E Q H; Chadwick, R G

    2012-12-01

    Temporary bridges must survive for their anticipated time in clinical service. Fibre reinforcement offers a potential means of increasing the chances of achieving this. This study sought to investigate this. This in vitro study determined the three point flexural strength and flexural fatigue characteristics of beam specimens (25 mm long × 3 mm wide × 2 mm deep) of a chairside temporary crown and bridge material (Protemp 4, 3M ESPE) and a laboratory resin composite (Ceramage, Shofu Inc.) in unreinforced and reinforced states. Reinforcement was provided by Everstick Crown and Bridge (Stick Tech Ltd.) and Ribbond THM (Ribbond Inc.). All testing was performed using an Instron Universal testing machine following one week of storage in distilled water at 37 °C. Fibre reinforcement with Everstick C&B significantly (P < 0.001) increased the mean flexural strengths of both materials. The flexural fatigue limits of both Protemp 4 and Ceramage were significantly (P < 0.001) increased by fibre incorporation. The observed fibre resin coupling (where Everstick C&B was used) and knitting together of fractured specimen fragments to restore specimen function (specimens where Ribbond THM was used) demonstrated the potential to enhance the durability of temporary bridges made of the materials studied here. The incorporation of fibre reinforcement in temporary bridge materials has the potential to enhance the longevity of temporary bridges and thus reduce the need for emergency treatment. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. 76 FR 59182 - Culturally Significant Objects Imported for Exhibition Determinations: “Impressionism...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-23

    ... DEPARTMENT OF STATE [Public Notice: 7610] Culturally Significant Objects Imported for Exhibition Determinations: ``Impressionism: Masterworks on Paper'' SUMMARY: Notice is hereby given of the following... ``Impressionism: Masterworks on Paper'' imported from abroad for temporary exhibition within the United States...

  11. 75 FR 3476 - Designation of Haiti for Temporary Protected Status

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-21

    ... Express mail and courier deliveries: USCIS, Attn: Haiti TPS, 2501 S. State Hwy. 121 Business, Suite 400... DEPARTMENT OF HOMELAND SECURITY U.S. Citizenship and Immigration Services [CIS No. 2491-10; DHS..., the Secretary is authorized to designate a foreign state for TPS or parts of such state upon finding...

  12. 26 CFR 54.9815-2713T - Coverage of preventive health services (temporary).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... the current recommendations of the United States Preventive Services Task Force with respect to the... States Preventive Services Task Force with respect to the individual. The provider bills the plan for an... A or B in the current recommendations of the United States Preventive Services Task Force with...

  13. 23 CFR 658.23 - LCV freeze; cargo-carrying unit freeze.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... safety purposes and road construction, a State may make minor adjustments of a temporary and emergency... decision is reached that minor adjustments made by a State are not legitimately attributable to road or bridge construction or safety, the FHWA will inform the State, and the original conditions of the freeze...

  14. Ground state destabilization from a positioned general base in the ketosteroid isomerase active site.

    PubMed

    Ruben, Eliza A; Schwans, Jason P; Sonnett, Matthew; Natarajan, Aditya; Gonzalez, Ana; Tsai, Yingssu; Herschlag, Daniel

    2013-02-12

    We compared the binding affinities of ground state analogues for bacterial ketosteroid isomerase (KSI) with a wild-type anionic Asp general base and with uncharged Asn and Ala in the general base position to provide a measure of potential ground state destabilization that could arise from the close juxtaposition of the anionic Asp and hydrophobic steroid in the reaction's Michaelis complex. The analogue binding affinity increased ~1 order of magnitude for the Asp38Asn mutation and ~2 orders of magnitude for the Asp38Ala mutation, relative to the affinity with Asp38, for KSI from two sources. The increased level of binding suggests that the abutment of a charged general base and a hydrophobic steroid is modestly destabilizing, relative to a standard state in water, and that this destabilization is relieved in the transition state and intermediate in which the charge on the general base has been neutralized because of proton abstraction. Stronger binding also arose from mutation of Pro39, the residue adjacent to the Asp general base, consistent with an ability of the Asp general base to now reorient to avoid the destabilizing interaction. Consistent with this model, the Pro mutants reduced or eliminated the increased level of binding upon replacement of Asp38 with Asn or Ala. These results, supported by additional structural observations, suggest that ground state destabilization from the negatively charged Asp38 general base provides a modest contribution to KSI catalysis. They also provide a clear illustration of the well-recognized concept that enzymes evolve for catalytic function and not, in general, to maximize ground state binding. This ground state destabilization mechanism may be common to the many enzymes with anionic side chains that deprotonate carbon acids.

  15. Enhancement of encaged electron concentration by Sr(2+) doping and improvement of Gd(3+) emission through controlling encaged anions in conductive C12A7 phosphors.

    PubMed

    Zhang, Meng; Liu, Yuxue; Zhu, Hancheng; Yan, Duanting; Yang, Jian; Zhang, Xinyang; Liu, Chunguang; Xu, Changshan

    2016-07-28

    Conductive C12A7:0.1%Gd(3+),y%Sr(2+) powders with different Sr(2+) doping concentrations have been prepared in a H2 atmosphere by a solid state method in combination with subsequent UV-irradiation. The encaged electron concentration could be modulated through tuning Sr(2+) doping and its maximum value reaches 2.3 × 10(19) cm(-3). This is attributed to the competition between enhanced uptake and the release of the encaged anions during their formation and diffusion processes and the suppression of encaged electrons generation due to the increased encaged OH(-) anions and the decreased encaged O(2-) anions. Although there exists encaged electrons and different encaged anions (O(2-), H(-) and OH(-)) in C12A7 conductive powders prepared through the hydrogen route, a dominant local environment around Gd(3+) could be observed using electron spin resonance (ESR) detection. It can be ascribed to the stronger coupling of the encaged OH(-) to the framework of C12A7 than those of the encaged electrons, O(2-) and H(-) anions. In addition, emission of Gd(3+) ions is enhanced under UV or low voltage electron beam excitation and a new local environment around Gd(3+) ions appears through the thermal annealing in air because of the decrease of the encaged OH(-) anions and the increase of the encaged O(2-) anions. Our results suggested that Sr(2+) doping in combination with thermal annealing in air is an effective strategy for increasing the conductive performance and enhancing the emission of rare earth ions doped into C12A7 conductive phosphors for low-voltage field emission displays (FEDs).

  16. Probing Intermolecular Electron Delocalization in Dimer Radical Anions by Vibrational Spectroscopy

    DOE PAGES

    Mani, Tomoyasu; Grills, David C.

    2017-07-05

    Delocalization of charges is one of the factors controlling charge transport in conjugated molecules. It is considered to play an important role in the performance of a wide range of molecular technologies, including organic solar cells and organic electronics. Dimerization reactions are well-suited as a model to investigate intermolecular spatial delocalization of charges. And while dimerization reactions of radical cations are well investigated, studies on radical anions are still scarce. Upon dimerization of radical anions with neutral counterparts, an electron is considered to delocalize over the two molecules. By using time-resolved infrared (TRIR) detection coupled with pulse radiolysis, we showmore » that radical anions of 4-n-hexyl-4'-cyanobiphenyl (6CB) undergo such dimerization reactions, with an electron equally delocalized over the two molecules. We have recently demonstrated that nitrile ν(C≡N) vibrations respond to the degree of electron localization of nitrile-substituted anions: we can quantify the changes in the electronic charges from the neutral to the anion states in the nitriles by monitoring the ν(C≡N) IR shifts. In the first part of this article, we show that the sensitivity of the ν(C≡N) IR shifts does not depend on solvent polarity. In the second part, we describe how probing the shifts of the nitrile IR vibrational band unambiguously confirms the formation of dimer radical anions, with K dim = 3 × 10 4 M –1. IR findings are corroborated by electronic absorption spectroscopy and electronic structure calculations. We find that the presence of a hexyl chain and the formation of π–π interactions are both crucial for dimerization of radical anions of 6CB with neutral 6CB. Our study provides clear evidence of spatial delocalization of electrons over two molecular fragments.« less

  17. Dissociative electron attachment to the gas-phase nucleobase hypoxanthine

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dawley, M. Michele; Tanzer, Katrin; Denifl, Stephan, E-mail: Stephan.Denifl@uibk.ac.at, E-mail: Sylwia.Ptasinska.1@nd.edu

    We present high-resolution measurements of the dissociative electron attachment (DEA) to isolated gas-phase hypoxanthine (C{sub 5}H{sub 4}N{sub 4}O, Hyp), a tRNA purine base. The anion mass spectra and individual ion efficiency curves from Hyp were measured as a function of electron energy below 9 eV. The mass spectra at 1 and 6 eV exhibit the highest anion yields, indicating possible common precursor ions that decay into the detectable anionic fragments. The (Hyp − H) anion (C{sub 5}H{sub 3}N{sub 4}O{sup −}) exhibits a sharp resonant peak at 1 eV, which we tentatively assign to a dipole-bound state of the keto-N1H,N9H tautomermore » in which dehydrogenation occurs at either the N1 or N9 position based upon our quantum chemical computations (B3LYP/6-311+G(d,p) and U(MP2-aug-cc-pVDZ+)) and prior studies with adenine. This closed-shell dehydrogenated anion is the dominant fragment formed upon electron attachment, as with other nucleobases. Seven other anions were also observed including (Hyp − NH){sup −}, C{sub 4}H{sub 3}N{sub 4}{sup −}/C{sub 4}HN{sub 3}O{sup −}, C{sub 4}H{sub 2}N{sub 3}{sup −}, C{sub 3}NO{sup −}/HC(HCN)CN{sup −}, OCN{sup −}, CN{sup −}, and O{sup −}. Most of these anions exhibit broad but weak resonances between 4 and 8 eV similar to many analogous anions from adenine. The DEA to Hyp involves significant fragmentation, which is relevant to understanding radiation damage of biomolecules.« less

  18. Ca2+ and Mg2+-enhanced reduction of arsenazo III to its anion free radical metabolite and generation of superoxide anion by an outer mitochondrial membrane azoreductase.

    PubMed

    Moreno, S N; Mason, R P; Docampo, R

    1984-12-10

    At the concentrations usually employed as a Ca2+ indicator, arsenazo III underwent a one-electron reduction by rat liver mitochondria to produce an azo anion radical as demonstrated by electron-spin resonance spectroscopy. Either NADH or NADPH could serve as a source of reducing equivalents for the production of this free radical by intact rat liver mitochondria. Under aerobic conditions, addition of arsenazo III to rat liver mitochondria produced an increase in electron flow from NAD(P)H to molecular oxygen, generating superoxide anion. NAD(P)H generated from endogenous mitochondrial NAD(P)+ by intramitochondrial reactions could not be used for the NAD(P)H azoreductase reaction unless the mitochondria were solubilized by detergent or anaerobiosis. In addition, NAD(P)H azoreductase activity was higher in the crude outer mitochondrial membrane fraction than in mitoplasts and intact mitochondria. The steady-state concentration of the azo anion radical and the arsenazo III-stimulated cyanide-insensitive oxygen consumption were enhanced by calcium and magnesium, suggesting that, in addition to an enhanced azo anion radical-stabilization by complexation with the metal ions, enhanced reduction of arsenazo III also occurred. Accordingly, addition of cations to crude outer mitochondrial membrane preparations increased arsenazo III-stimulated cyanide-insensitive O2 consumption, H2O2 formation, and NAD(P)H oxidation. Antipyrylazo III was much less effective than arsenazo III in increasing superoxide anion formation by rat liver mitochondria and gave a much weaker electron spin resonance spectrum of an azo anion radical. These results provide direct evidence of an azoreductase activity associated with the outer mitochondrial membrane and of a stimulation of arsenazo III reduction by cations.

  19. Role of Phosphate and Other Proton-Donating Anions in Respiration-Coupled Transport of Ca2+ by Mitochondria

    PubMed Central

    Lehninger, Albert L.

    1974-01-01

    Measurements of extra oxygen consumption, 45Ca2+ uptake, and the osmotic expansion of the matrix compartment show that not all permeant anions are capable of supporting and accompanying the energy-dependent transport of Ca2+ from the medium into the matrix in respiring rat-liver mitochondria. Phosphate, arsenate, acetate, butyrate, β-hydroxybutyrate, lactate, and bicarbonate + CO2 supported Ca2+ uptake, whereas the permeant anions, nitrate, thiocyanate, chlorate, and perchlorate, did not. The active anions share a common denominator, the potential ability to donate a proton to the mitochondrial matrix; the inactive anions lack this capacity. Phosphate and the other active permeant anions move into the matrix in response to the alkaline-inside electrochemical gradient of protons generated across the mitochondrial membrane by electron transport, thus forming a negative-inside anion gradient. It is postulated that the latter gradient is the immediate “pulling” force for the influx of Ca2+ on the electrogenic Ca2+ carrier in respiring mitochondria under intracellular conditions. Since mitochondria in the cell are normally exposed to an excess of phosphate (and the bicarbonate-CO2 system), particularly in state 4, inward transport of these proton-yielding anions probably precedes and is necessary for inward transport of Ca2+ and other cations under biological conditions. These observations indicate that a negative-inside gradient of phosphate generated by electron transport is a common step and provides the immediate motive power not only for (a) the inward transport of dicarboxylates and tricarboxylates and (b) the energy-dependent exchange of external ADP3- for internal ATP4- during oxidative phosphorylation, as has already been established, but also for (c) the inward transport of Ca2+, K+, and other cations. PMID:4364542

  20. Comparison of Anion Reorientational Dynamics in MCB 9 H 10 and M 2 B 10 H 10 (M = Li, Na) via Nuclear Magnetic Resonance and Quasielastic Neutron Scattering Studies

    DOE PAGES

    Soloninin, Alexei V.; Dimitrievska, Mirjana; Skoryunov, Roman V.; ...

    2016-12-13

    The disordered phases of the 1-carba-closo-decaborates LiCB9H10 and NaCB9H10 exhibit the best solid-state ionic conductivities to date among all known polycrystalline competitors, likely facilitated in part by the highly orientationally mobile CB9H10- anions. We have undertaken both NMR and quasielastic neutron scattering (QENS) measurements to help characterize the monovalent anion reorientational mobilities and mechanisms associated with these two compounds and to compare their anion reorientational behaviors with those for the divalent B10H102- anions in the related Li2B10H10 and Na2B10H10 compounds. NMR data show that the transition from the low-T ordered to the high-T disordered phase for both LiCB9H10 and NaCB9H10more » is accompanied by a nearly two-orders-of-magnitude increase in the reorientational jump rate of CB9H10- anions. QENS measurements of the various disordered compounds indicate anion jump correlation frequencies on the order of 1010-1011 s-1 and confirm that NaCB9H10 displays jump frequencies about 60% to 120% higher than those for LiCB9H10 and Na2B10H10 at comparable temperatures. The Q-dependent quasielastic scattering suggests similar small-angular-jump reorientational mechanisms for the different disordered anions, changing from more uniaxial in character at lower temperatures to more multidimensional at higher temperatures, although still falling short of full three-dimensional rotational diffusion below 500 K within the nanosecond neutron window.« less

  1. Ion counting in supercapacitor electrodes using NMR spectroscopy.

    PubMed

    Griffin, John M; Forse, Alexander C; Wang, Hao; Trease, Nicole M; Taberna, Pierre-Louis; Simon, Patrice; Grey, Clare P

    2014-01-01

    (19)F NMR spectroscopy has been used to study the local environments of anions in supercapacitor electrodes and to quantify changes in the populations of adsorbed species during charging. In the absence of an applied potential, anionic species adsorbed within carbon micropores (in-pore) are distinguished from those in large mesopores and spaces between particles (ex-pore) by a characteristic nucleus-independent chemical shift (NICS). Adsorption experiments and two-dimensional exchange experiments confirm that anions are in dynamic equilibrium between the in- and ex-pore environments with an exchange rate in the order of tens of Hz. (19)F in situ NMR spectra recorded at different charge states reveal changes in the intensity and NICS of the in-pore resonances, which are interpreted in term of changes in the population and local environments of the adsorbed anions that arise due to the charge-storage process. A comparison of the results obtained for a range of electrolytes reveals that several factors influence the charging mechanism. For a tetraethylammonium tetrafluoroborate electrolyte, positive polarisation of the electrode is found to proceed by anion adsorption at a low concentration, whereas increased ion exchange plays a more important role for a high concentration electrolyte. In contrast, negative polarization of the electrode proceeds by cation adsorption for both concentrations. For a tetrabutylammonium tetrafluoroborate electrolyte, anion expulsion is observed in the negative charging regime; this is attributed to the reduced mobility and/or access of the larger cations inside the pores, which forces the expulsion of anions in order to build up ionic charge. Significant anion expulsion is also observed in the negative charging regime for alkali metal bis(trifluoromethane)sulfonimide electrolytes, suggesting that more subtle factors also affect the charging mechanism.

  2. Effects of hydrology on zooplankton communities in high-mountain ponds, Mount Rainier National Park, USA

    USGS Publications Warehouse

    Girdner, Scott; Larson, Gary L.

    1995-01-01

    Ten high-mountain ponds in Mount Rainier National Park, Washington State, were studied from ice-out in June through September1992 to investigate the influences of fluctuating pond volumes on zooplankton communities. All of the ponds were at maximum volume immediately after ice-out. The temporary pond with the shortest wet phase was inhabited by rotifer taxa with short generation times and a crustacean taxon with the ability to encyst as drought-resistant resting bodies at immature stages of development. Dominant zooplankton taxa in three other temporary ponds and six permanent ponds were similar. Rotifer densities typically were lower in temporary ponds relative to those in permanent ponds, although Brachionus urceolaris was abundant shortly before the temporary ponds dried. Large volume loss was associated with large declines in total abundances of crustacean populations. Daphnia rosea was not present in temporary ponds following fall recharge. In deep-permanent ponds, copepods had slower developmental rates, smaller temporal changes in total abundances of crustacean populations and two additional large-bodied crustacean taxa were present relative to the characteristics of crustacean communities in shallow-permanent ponds. Owing to their small sizes and sensitivity to environmental change, collectively ponds such as these may provide an early signal of long-term climate change in aquatic systems.

  3. Bound and resonance states of the dipolar anion of hydrogen cyanide: Competition between threshold effects and rotation in an open quantum system

    DOE PAGES

    Fossez, K.; Michel, N.; Nazarewicz, W.; ...

    2015-01-12

    In this paper, bound and resonance states of the dipole-bound anion of hydrogen cyanide HCN – are studied using a nonadiabatic pseudopotential method and the Berggren expansion technique involving bound states, decaying resonant states, and nonresonant scattering continuum. We devise an algorithm to identify the resonant states in the complex energy plane. To characterize spatial distributions of electronic wave functions, we introduce the body-fixed density and use it to assign families of resonant states into collective rotational bands. We find that the nonadiabatic coupling of electronic motion to molecular rotation results in a transition from the strong-coupling to weak-coupling regime.more » In the strong-coupling limit, the electron moving in a subthreshold, spatially extended halo state follows the rotational motion of the molecule. Above the ionization threshold, the electron's motion in a resonance state becomes largely decoupled from molecular rotation. Finally, the widths of resonance-band members depend primarily on the electron orbital angular momentum.« less

  4. The effects of paid maternity leave: Evidence from Temporary Disability Insurance.

    PubMed

    Stearns, Jenna

    2015-09-01

    This paper investigates the effects of a large-scale paid maternity leave program on birth outcomes in the United States. In 1978, states with Temporary Disability Insurance (TDI) programs were required to start providing wage replacement benefits to pregnant women, substantially increasing access to antenatal and postnatal paid leave for working mothers. Using natality data, I find that TDI paid maternity leave reduces the share of low birth weight births by 3.2 percent, and the estimated treatment-on-the-treated effect is over 10 percent. It also decreases the likelihood of early term birth by 6.6 percent. Paid maternity leave has particularly large impacts on the children of unmarried and black mothers. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Weight Gain in Survivors Living in Temporary Housing in the Tsunami-Stricken Area during the Recovery Phase following the Great East Japan Earthquake and Tsunami.

    PubMed

    Takahashi, Shuko; Yonekura, Yuki; Sasaki, Ryohei; Yokoyama, Yukari; Tanno, Kozo; Sakata, Kiyomi; Ogawa, Akira; Kobayashi, Seichiro; Yamamoto, Taro

    2016-01-01

    Survivors who lost their homes in the Great East Japan Earthquake and Tsunami were forced to live in difficult conditions in temporary housing several months after the disaster. Body weights of survivors living in temporary housing for a long period might increase due to changes in their life style and psychosocial state during the medium-term and long-term recovery phases. The aim of this study was to determine whether there were differences between body weight changes of people living in temporary housing and those not living in temporary housing in a tsunami-stricken area during the medium-term and long-term recovery phases. Health check-ups were performed about 7 months after the disaster (in 2011) and about 18 months after the disaster (in 2012) for people living in a tsunami-stricken area (n = 6,601, mean age = 62.3 y). We compared the changes in body weight in people living in temporary housing (TH group, n = 2,002) and those not living in temporary housing (NTH group, n = 4,599) using a multiple linear regression model. While there was no significant difference between body weights in the TH and NTH groups in the 2011 survey, there was a significant difference between the mean changes in body weight in both sexes. We found that the changes in body weight were significantly greater in the TH group than in the NTH group in both sexes. The partial regression coefficients of mean change in body weight were +0.52 kg (P-value < 0.001) in males in the TH group and +0.56 kg (P-value < 0.001) in females in the TH group (reference: NTH group). Analysis after adjustment for life style, psychosocial factors and cardiovascular risk factors found that people living in temporary housing in the tsunami- stricken area had a significant increase in body weight.

  6. Weight Gain in Survivors Living in Temporary Housing in the Tsunami-Stricken Area during the Recovery Phase following the Great East Japan Earthquake and Tsunami

    PubMed Central

    Yonekura, Yuki; Sasaki, Ryohei; Yokoyama, Yukari; Tanno, Kozo; Sakata, Kiyomi; Ogawa, Akira; Kobayashi, Seichiro; Yamamoto, Taro

    2016-01-01

    Introduction Survivors who lost their homes in the Great East Japan Earthquake and Tsunami were forced to live in difficult conditions in temporary housing several months after the disaster. Body weights of survivors living in temporary housing for a long period might increase due to changes in their life style and psychosocial state during the medium-term and long-term recovery phases. The aim of this study was to determine whether there were differences between body weight changes of people living in temporary housing and those not living in temporary housing in a tsunami-stricken area during the medium-term and long-term recovery phases. Materials and methods Health check-ups were performed about 7 months after the disaster (in 2011) and about 18 months after the disaster (in 2012) for people living in a tsunami-stricken area (n = 6,601, mean age = 62.3 y). We compared the changes in body weight in people living in temporary housing (TH group, n = 2,002) and those not living in temporary housing (NTH group, n = 4,599) using a multiple linear regression model. Results While there was no significant difference between body weights in the TH and NTH groups in the 2011 survey, there was a significant difference between the mean changes in body weight in both sexes. We found that the changes in body weight were significantly greater in the TH group than in the NTH group in both sexes. The partial regression coefficients of mean change in body weight were +0.52 kg (P-value < 0.001) in males in the TH group and +0.56 kg (P-value < 0.001) in females in the TH group (reference: NTH group). Conclusion Analysis after adjustment for life style, psychosocial factors and cardiovascular risk factors found that people living in temporary housing in the tsunami- stricken area had a significant increase in body weight. PMID:27907015

  7. Molecular Dynamics Simulation Study of Solvent and State of Charge Effects on Solid-Phase Structure and Counterion Binding in a Nitroxide Radical Containing Polymer Energy Storage Material

    DOE PAGES

    Kemper, Travis W.; Gennett, Thomas; Larsen, Ross E.

    2016-10-19

    Here we performed molecular dynamics simulations to understand the effects of solvent swelling and state of charge (SOC) on the redox active, organic radical cathode material poly(2,2,6,6-tetramethylpiperidinyloxy methacrylate) (PTMA). We show that the polar solvent acetonitrile primarily solvates the nitroxide radical without disrupting the packing of the (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) pendant groups of PTMA. We also simulated bulk PTMA in different SOC, 25%, 50%, 75%, and 100%, by converting the appropriate number of TEMPO groups to the cation charge state and adding BF 4 - counterions to the simulation. At each SOC the packing of PTMA, the solvent, and the counterionsmore » were examined. The binding of the anion to the nitroxide cation site was examined using the potential of mean force and found to be on the order of tens of meV, with a binding energy that decreased with increasing SOC. Additionally, we found that the cation state is stabilized by the presence of a nearby anion by more than 1 eV, and the implications of this stabilization on charge transport are discussed. Finally, we describe the implications of our results for how the SOC of an organic electrode affects electron and anion charge transport during the charging and discharging processes.« less

  8. The role of the anionic and cationic pt sites in the adsorption site preference of water and ethanol on defected Pt4/Pt(111) substrates: A density functional theory investigation within the D3 van der waals corrections

    NASA Astrophysics Data System (ADS)

    Seminovski, Yohanna; Amaral, Rafael C.; Tereshchuk, Polina; Da Silva, Juarez L. F.

    2018-01-01

    Platinum (Pt) atoms in the bulk face-centered cubic structure have neutral charge because they are equivalent by symmetry, however, in clean Pt surfaces, the effective charge on Pt atoms can turn slightly negative (anionic) or positive (cationic) while increasing substantially in magnitude for defected (low-coordinated) Pt sites. The effective charge affect the adsorption properties of molecular species on Pt surfaces and it can compete in importance with the coupling of the substrate-molecule electronic states. Although several studies have been reported due to the importance of Pt for catalysis, our understanding of the role played by low-coordinated sites is still limited. Here, we employ density functional theory within the Perdew-Burke-Ernzerhof exchange-correlation functional and the D3 van der Waals (vdW) correction to investigate the role of the cationic and anionic Pt sites on the adsorption properties of ethanol and water on defected Pt4/Pt(111) substrates. Four substrates were carefully selected, namely, two two-dimensional (2D) Pt4 configurations (2D-strand and 2D-island) and two tri-dimensional (3D) Pt4 (3D-fcc and 3D-hcp), to understand the role of coordination, effective charge, and coupling of the electronic states in the adsorption properties. From the Bader charge analysis, we identified the cationic and anionic sites among the Pt atoms exposed to the vacuum region in the Pt4/Pt(111) substrates. We found that ethanol and water bind via the anionic O atoms to the low-coordinated defected Pt sites of the substrates, where the angle PtOH is nearly 100° for most configurations. In the 3D-fcc or 3D-hcp defected configurations, the lowest-coordinated Pt atoms are anionic, hence, those Pt sites are not preferable for the adsorption of O atoms. The charge transfer from water and ethanol to the Pt substrates has similar magnitude for all cases, which implies similar Coulomb contribution to the adsorption energy. Moreover, we found a correlation of the adsorption energy with the shift of the center of gravity of the occupied d-states of Pt sites.

  9. Stabilization of very rare tautomers of uracil by an excess electron.

    PubMed

    Bachorz, Rafał A; Rak, Janusz; Gutowski, Maciej

    2005-05-21

    We characterized valence-type and dipole-bound anionic states of uracil using various electronic structure methods. We found that the most stable anion is related to neither the canonical 2,4-dioxo nor a rare imino-hydroxy tautomer. Instead, it is related to an imino-oxo tautomer, in which the N1H proton is transferred to the C5 atom. This valence anion is characterized by an electron vertical detachment energy (VDE) of 1267 meV and it is adiabatically stable with respect to the canonical neutral by 3.93 kcal mol(-1). It is also more stable by 2.32 and 5.10 kcal mol(-1) than the dipole-bound and valence anion, respectively, of the canonical tautomer. The VDE values for the former and the latter are 73 and 506 meV, respectively. Another, anionic, low-lying imino-oxo tautomer with a VDE of 2499 meV has a proton transferred from N3H to C5. It is less stable than the neutral canonical tautomer by 1.38 kcal mol(-1). The mechanism of formation of anionic tautomers with the carbon C5 protonated may involve intermolecular proton transfer or dissociative electron attachment to the canonical neutral tautomer followed by a barrier-free attachment of a hydrogen atom to C5. The six-member ring structure of anionic tautomers with carbon atoms protonated might be unstable upon an excess electron detachment. Indeed, the neutral systems resulting from electron detachment from anionic tautomers with carbon atoms protonated evolve along barrier-free decomposition pathways to a linear or a bicyclo structure, which might be viewed as lesions to RNA. Within the PCM hydration model, the low-lying valence anions become adiabatically bound with respect to the canonical neutral and the two most stable tautomers have carbon atoms protonated.

  10. 77 FR 26814 - Culturally Significant Objects Imported for Exhibition Determinations: “Modern Landscapes”

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-07

    ... DEPARTMENT OF STATE [Public Notice 7870] Culturally Significant Objects Imported for Exhibition Determinations: ``Modern Landscapes'' SUMMARY: Notice is hereby given of the following determinations: Pursuant... Landscapes,'' imported from abroad for temporary exhibition within the United States, are of cultural...

  11. 20 CFR 655.3 - Special procedures.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process and Enforcement of Attestations for Temporary Employment in Occupations Other Than Agriculture or Registered Nursing in the United States (H-2B Workers) § 655.3 Special procedures. (a) Systematic process. This subpart provides procedures for the...

  12. 41 CFR 60-1.26 - Enforcement proceedings.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., the Attorney General may bring a civil action in the appropriate district court of the United States... civil action in the appropriate district court of the United States requesting a temporary restraining... Contracts OFFICE OF FEDERAL CONTRACT COMPLIANCE PROGRAMS, EQUAL EMPLOYMENT OPPORTUNITY, DEPARTMENT OF LABOR...

  13. 78 FR 4972 - Culturally Significant Objects Imported for Exhibition Determinations: “Chagall: Beyond Color”

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-23

    ... DEPARTMENT OF STATE [Public Notice 8158] Culturally Significant Objects Imported for Exhibition Determinations: ``Chagall: Beyond Color'' SUMMARY: Notice is hereby given of the following determinations... Color,'' imported from abroad for temporary exhibition within the United States, are of cultural...

  14. Probing structure, thermochemistry, electron affinity, and magnetic moment of thulium-doped silicon clusters TmSi n (n = 3-10) and their anions with density functional theory.

    PubMed

    Huang, Xintao; Yang, Jucai

    2017-12-26

    The most stable structures and electronic properties of TmSi n (n = 3-10) clusters and their anions have been probed by using the ABCluster global search technique combined with the PBE, TPSSh, and B3LYP density functional methods. The results revealed that the most stable structures of neutral TmSi n and their anions can be regarded as substituting a Si atom of the ground state structure of Si n + 1 with a Tm atom. The reliable AEAs, VDEs and simulated PES of TmSi n (n = 3-10) are presented. Calculations of HOMO-LUMO gap revealed that introducing Tm atom to Si cluster can improve photochemical reactivity of the cluster. The NPA analyses indicated that the 4f electron of Tm atom in TmSi n (n = 3-10) and their anions do not participate in bonding. The total magnetic moments of TmSi n are mainly provided by the 4f electrons of Tm atom. The dissociation energy of Tm atom from the most stable structure of TmSi n and their anions has been calculated to examine relative stability.

  15. Cation and anion sequences in dark-adapted Balanus photoreceptor

    PubMed Central

    1977-01-01

    Anion and cation permeabilities in dark-adapted Balanus photoreceptors were determined by comparing changes in the membrane potential in response to replacement of the dominant anion (Cl-) or cation (Na+) by test anions or cations in the superfusing solution. The anion permeability sequence obtained was PI greater than PSO4 greater than PBr greater than PCl greater than Pisethionate greater than Pmethanesulfonate. Gluconate, glucuronate, and glutamate generally appeared more permeable and propionate less permeable than Cl-. The alkali-metal cation permeability sequence obtained was PK greater than PRb greater than PCx greater than PNa approximately PLi. This corresponds to Eisenman's IV which is the same sequencethat has been obtained for other classes of nerve cells in the resting state. The values obtained for the permeability ratios of the alkali-metal cations are considered to be minimal. The membrane conductance measured by passing inward current pulses in the different test cations followed the sequence, GK greater than GRb greater than GCs greater than GNa greater than GLi. The conductance ratios obtained for a full substitution of the test cation agreed quite well with permeability ratios for all the alkali-metal cations except K+ which was generally higher. PMID:199688

  16. Study of MoVO(y) (y = 2-5) anion and neutral clusters using anion photoelectron spectroscopy and density functional theory calculations.

    PubMed

    Mann, Jennifer E; Rothgeb, David W; Waller, Sarah E; Jarrold, Caroline Chick

    2010-10-28

    The vibrationally resolved anion photoelectron (PE) spectra of MoVO(y)(-) (y = 2 - 5) metal suboxide clusters are presented and analyzed in the context of density functional theory (DFT) calculations. The electronically congested spectra reflect an increase in cluster electron affinity with increasing oxidation state. Ion beam hole-burning results reveal the features in the PE spectra of MoVO(2)(-) and MoVO(4)(-) are a result of only one anion isomer, while at least two isomers contribute to electronic structure observed in the PE spectrum of MoVO(3)(-). Spectral features of the binary systems are compared to their pure analogs, Mo(2)O(y) and V(2)O(y). An attempt to characterize the anion and neutral electronic and molecular structures is made by comparison with results from DFT calculations. However, reconciliation between the cluster spectra and the calculated spectroscopic parameters is not as straightforward as in previous studies on similar systems (Yoder, B. L.; Maze, J. T.; Raghavachari, K.; Jarrold, C. C. J. Chem. Phys. 2005, 122, 094313 and Mayhall, N. J.; Rothgeb, D. W.; Hossain, E.; Raghavachari, K.; Jarrold, C. C. J. Chem. Phys. 2009, 130, 124313).

  17. States With Medically Needy Pathways: Differences in Long-Term and Temporary Medicaid Entry for Low-Income Medicare Beneficiaries.

    PubMed

    Keohane, Laura M; Trivedi, Amal; Mor, Vincent

    2017-10-01

    Medically needy pathways may provide temporary catastrophic coverage for low-income Medicare beneficiaries who do not otherwise qualify for full Medicaid benefits. Between January 2009 and June 2010, states with medically needy pathways had a higher percentage of low-income beneficiaries join Medicaid than states without such programs (7.5% vs. 4.1%, p < .01). However, among new full Medicaid participants, living in a state with a medically needy pathway was associated with a 3.8 percentage point (adjusted 95% confidence interval [1.8, 5.8]) increase in the probability of switching to partial Medicaid and a 4.5 percentage point (adjusted 95% confidence interval [2.9, 6.2]) increase in the probability of exiting Medicaid within 12 months. The predicted risk of leaving Medicaid was greatest when new Medicaid participants used only hospital services, rather than nursing home services, in their first month of Medicaid benefits. Alternative strategies for protecting low-income Medicare beneficiaries' access to care could provide more stable coverage.

  18. The Possible Interstellar Anion CH2CN-: Spectroscopic Constants, Vibrational Frequencies, and Other Considerations

    NASA Technical Reports Server (NTRS)

    Fortenberry, Ryan C.; Crawford, T. Daniel; Lee, Timothy J.

    2012-01-01

    The A 1B1 <-1A0 excitation into the dipole-bound state of the cyanomethyl anion (CH2CN??) has been hypothesized as the carrier for one di use interstellar band. However, this particular molecular system has not been detected in the interstellar medium even though the related cyanomethyl radical and the isoelectronic ketenimine molecule have been found. In this study we are employing the use of proven quartic force elds and second-order vibrational perturbation theory to compute accurate spectroscopic constants and fundamental vibrational frequencies for X 1A0 CH2CN?? in order to assist in laboratory studies and astronomical observations. Keywords: Astrochemistry, ISM: molecular anions, Quartic force elds, Rotational constants, Vibrational frequencies

  19. Ion-momentum imaging of dissociative attachment of electrons to molecules

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Slaughter, D. S.; Belkacem, A.; McCurdy, C. W.

    Here, we present an overview of experiments and theory relevant to dissociative electron attachment studied by momentum imaging. We describe several key examples of characteristic transient anion dynamics in the form of small polyatomic electron-molecule systems. In each of these examples the so-called axial recoil approximation is found to break down due to correlation of the electronic and nuclear degrees of freedom of the transient anion. Guided by anion fragment momentum measurements and predictions of the electron scattering attachment probability in the molecular frame, we demonstrate that accurate predictions of the dissociation dynamics can be achieved without a detailed investigationmore » of the surface topology of the relevant electronic states or the fragment trajectories on those surfaces.« less

  20. Ion-momentum imaging of dissociative attachment of electrons to molecules

    DOE PAGES

    Slaughter, D. S.; Belkacem, A.; McCurdy, C. W.; ...

    2016-10-24

    Here, we present an overview of experiments and theory relevant to dissociative electron attachment studied by momentum imaging. We describe several key examples of characteristic transient anion dynamics in the form of small polyatomic electron-molecule systems. In each of these examples the so-called axial recoil approximation is found to break down due to correlation of the electronic and nuclear degrees of freedom of the transient anion. Guided by anion fragment momentum measurements and predictions of the electron scattering attachment probability in the molecular frame, we demonstrate that accurate predictions of the dissociation dynamics can be achieved without a detailed investigationmore » of the surface topology of the relevant electronic states or the fragment trajectories on those surfaces.« less

  1. Super-pnicogen bonding in the radical anion of the fluorophosphine dimer

    NASA Astrophysics Data System (ADS)

    Setiawan, Dani; Cremer, Dieter

    2016-10-01

    The LUMO of the pnicogen-bonded fluoro-phosphine dimer has PP bonding character. Radical anion and dianion form relatively strong pnicogen bonds with some covalent character where however the dianion turns out to be a second order transition state. The binding energy of (FPH 2)2- is 30.4 kcal/mol (CCSD(T)/aug-cc-pVTZ; CASPT2(5,8): 30.7 kcal/mol) and the bond strength order measured with the local PP bond stretching force constant increases from 0.055 for the neutral dimer to 0.187 thus revealing that the stabilization of the radical anion is to a large extend a result of one-electron six-center delocalization. Pnicogen-bonded complexes have a stabilizing electron affinity.

  2. Effects of redox-active interlayer anions on the oxygen evolution reactivity of NiFe-layered double hydroxide nanosheets

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zhou, Daojin; Cai, Zhao; Bi, Yongmin

    Nickel-iron layered double hydroxide (NiFe-LDH) nanosheets have shown optimal oxygen evolution reaction (OER) performance; however, the role of the intercalated ions in the OER activity remains unclear. In this work, we show that the activity of the NiFe-LDHs can be tailored by the intercalated anions with different redox potentials. The intercalation of anions with low redox potential (high reducing ability), such as hypophosphites, leads to NiFe-LDHs with low OER overpotential of 240 mV and a small Tafel slope of 36.9 mV/dec, whereas NiFe-LDHs intercalated with anions of high redox potential (low reducing ability), such as fluorion, show a high overpotentialmore » of 370 mV and a Tafel slope of 80.8 mV/dec. The OER activity shows a surprising linear correlation with the standard redox potential. Density functional theory calculations and X-ray photoelectron spectroscopy analysis indicate that the intercalated anions alter the electronic structure of metal atoms which exposed at the surface. Anions with low standard redox potential and strong reducing ability transfer more electrons to the hydroxide layers. Finally, this increases the electron density of the surface metal sites and stabilizes their high-valence states, whose formation is known as the critical step prior to the OER process.« less

  3. Functional anion concept: effect of fluorine anion on hydrogen storage of sodium alanate.

    PubMed

    Yin, Li-Chang; Wang, Ping; Kang, Xiang-Dong; Sun, Cheng-Hua; Cheng, Hui-Ming

    2007-03-28

    Doping NaAlH(4) with Ti-catalyst has produced a promising hydrogen storage system that can be reversibly operated at moderate temperature conditions. Of the various dopant precursors, TiCl(3) was well recognized due to its pronounced catalytic effect on the reversible dehydrogenation processes of sodium aluminium hydrides. Quite recently we experimentally found that TiF(3) was even better than TiCl(3) in terms of the critical hydrogen storage properties of the doped hydrides, in particular the dehydriding performance at Na(3)AlH(6)/NaH + Al step at moderate temperature. We present here the DFT calculation results of the TiF(3) or TiCl(3) doped Na(3)AlH(6). Our computational studies have demonstrated that F(-) and Cl(-) anions differ substantially from each other with regard to the state and function in the doped sodium aluminium hydride. In great contrast to the case of chloride doping where Cl(-) anion constitutes the "dead weight" NaCl, the fluoride doping results in a substitution of H(-) by F(-) anion in the hydride lattice and accordingly, a favorable thermodynamics adjustment. These results well explain the observed dehydriding performance associated with TiF(3)/TiCl(3)-doping. More significantly, the coupled computational and experimental efforts allow us to put forward a "functional anion" concept. This renews the current mechanism understanding in the catalytically enhanced sodium alanate.

  4. Effects of redox-active interlayer anions on the oxygen evolution reactivity of NiFe-layered double hydroxide nanosheets

    DOE PAGES

    Zhou, Daojin; Cai, Zhao; Bi, Yongmin; ...

    2018-02-02

    Nickel-iron layered double hydroxide (NiFe-LDH) nanosheets have shown optimal oxygen evolution reaction (OER) performance; however, the role of the intercalated ions in the OER activity remains unclear. In this work, we show that the activity of the NiFe-LDHs can be tailored by the intercalated anions with different redox potentials. The intercalation of anions with low redox potential (high reducing ability), such as hypophosphites, leads to NiFe-LDHs with low OER overpotential of 240 mV and a small Tafel slope of 36.9 mV/dec, whereas NiFe-LDHs intercalated with anions of high redox potential (low reducing ability), such as fluorion, show a high overpotentialmore » of 370 mV and a Tafel slope of 80.8 mV/dec. The OER activity shows a surprising linear correlation with the standard redox potential. Density functional theory calculations and X-ray photoelectron spectroscopy analysis indicate that the intercalated anions alter the electronic structure of metal atoms which exposed at the surface. Anions with low standard redox potential and strong reducing ability transfer more electrons to the hydroxide layers. Finally, this increases the electron density of the surface metal sites and stabilizes their high-valence states, whose formation is known as the critical step prior to the OER process.« less

  5. Evidence for halogen bond covalency in acyclic and interlocked halogen-bonding receptor anion recognition

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Robinson, Sean W.; Mustoe, Chantal L.; White, Nicholas G.

    The synthesis and anion binding properties of novel halogen-bonding (XB) bis-iodotriazole-pyridinium-containing acyclic and [2]catenane anion host systems are described. The XB acyclic receptor displays selectivity for acetate over halides with enhanced anion recognition properties compared to the analogous hydrogen-bonding (HB) acyclic receptor. A reversal in halide selectivity is observed in the XB [2]catenane, in comparison to the acyclic XB receptor, due to the interlocked host’s unique three-dimensional binding cavity, and no binding is observed for oxoanions. Notable halide anion association constant values determined for the [2]catenane in competitive organic–aqueous solvent mixtures demonstrate considerable enhancement of anion recognition as compared tomore » the HB catenane analogue. X-ray crystallographic analysis of a series of halide catenane complexes reveal strong XB interactions in the solid state. These interactions were studied using Cl and Br K-edge X-ray Absorption Spectroscopy (XAS) indicating intense pre-edge features characteristic of charge transfer from the halide to its bonding partner (σ AX←X–* ← X1s), and providing a direct measure of the degree of covalency in the halogen bond(s). Lastly, the data reveal that the degree of covalency is similar to that which is observed in transition metal coordinate covalent bonds. These results are supported by DFT results, which correlate well with the experimental data.« less

  6. Evidence for halogen bond covalency in acyclic and interlocked halogen-bonding receptor anion recognition

    DOE PAGES

    Robinson, Sean W.; Mustoe, Chantal L.; White, Nicholas G.; ...

    2014-12-05

    The synthesis and anion binding properties of novel halogen-bonding (XB) bis-iodotriazole-pyridinium-containing acyclic and [2]catenane anion host systems are described. The XB acyclic receptor displays selectivity for acetate over halides with enhanced anion recognition properties compared to the analogous hydrogen-bonding (HB) acyclic receptor. A reversal in halide selectivity is observed in the XB [2]catenane, in comparison to the acyclic XB receptor, due to the interlocked host’s unique three-dimensional binding cavity, and no binding is observed for oxoanions. Notable halide anion association constant values determined for the [2]catenane in competitive organic–aqueous solvent mixtures demonstrate considerable enhancement of anion recognition as compared tomore » the HB catenane analogue. X-ray crystallographic analysis of a series of halide catenane complexes reveal strong XB interactions in the solid state. These interactions were studied using Cl and Br K-edge X-ray Absorption Spectroscopy (XAS) indicating intense pre-edge features characteristic of charge transfer from the halide to its bonding partner (σ AX←X–* ← X1s), and providing a direct measure of the degree of covalency in the halogen bond(s). Lastly, the data reveal that the degree of covalency is similar to that which is observed in transition metal coordinate covalent bonds. These results are supported by DFT results, which correlate well with the experimental data.« less

  7. Molecular structure and interactions in the ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide.

    PubMed

    Dhumal, Nilesh R; Noack, Kristina; Kiefer, Johannes; Kim, Hyung J

    2014-04-03

    Electronic structure theory (density functional and Møller-Plesset perturbation theory) and vibrational spectroscopy (FT-IR and Raman) are employed to study molecular interactions in the room-temperature ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide. Different conformers of a cation-anion pair based on their molecular interactions are simulated in the gas phase and in a dielectric continuum solvent environment. Although the ordering of conformers in energy varies with theoretical methods, their predictions for three lowest energy conformers in the gas phase are similar. Strong C-H---N interactions between the acidic hydrogen atom of the cation imidazole ring and the nitrogen atom of the anion are predicted for either the lowest or second lowest energy conformer. In a continuum solvent, different theoretical methods yield the same ion-pair conformation for the lowest energy state. In both phases, the density functional method predicts that the anion is in a trans conformation in the lowest energy ion pair state. The theoretical results are compared with experimental observations from Raman scattering and IR absorption spectroscopies and manifestations of the molecular interactions in the vibrational spectra are discussed. The directions of the frequency shifts of the characteristic vibrations relative to the free anion and cation are explained by calculating the difference electron density coupled with electron density topography.

  8. Photoelectron angular distributions for states of any mixed character: An experiment-friendly model for atomic, molecular, and cluster anions

    NASA Astrophysics Data System (ADS)

    Khuseynov, Dmitry; Blackstone, Christopher C.; Culberson, Lori M.; Sanov, Andrei

    2014-09-01

    We present a model for laboratory-frame photoelectron angular distributions in direct photodetachment from (in principle) any molecular orbital using linearly polarized light. A transparent mathematical approach is used to generalize the Cooper-Zare central-potential model to anionic states of any mixed character. In the limit of atomic-anion photodetachment, the model reproduces the Cooper-Zare formula. In the case of an initial orbital described as a superposition of s and p-type functions, the model yields the previously obtained s-p mixing formula. The formalism is further advanced using the Hanstorp approximation, whereas the relative scaling of the partial-wave cross-sections is assumed to follow the Wigner threshold law. The resulting model describes the energy dependence of photoelectron anisotropy for any atomic, molecular, or cluster anions, usually without requiring a direct calculation of the transition dipole matrix elements. As a benchmark case, we apply the p-d variant of the model to the experimental results for NO- photodetachment and show that the observed anisotropy trend is described well using physically meaningful values of the model parameters. Overall, the presented formalism delivers insight into the photodetachment process and affords a new quantitative strategy for analyzing the photoelectron angular distributions and characterizing mixed-character molecular orbitals using photoelectron imaging spectroscopy of negative ions.

  9. Photoelectron angular distributions for states of any mixed character: an experiment-friendly model for atomic, molecular, and cluster anions.

    PubMed

    Khuseynov, Dmitry; Blackstone, Christopher C; Culberson, Lori M; Sanov, Andrei

    2014-09-28

    We present a model for laboratory-frame photoelectron angular distributions in direct photodetachment from (in principle) any molecular orbital using linearly polarized light. A transparent mathematical approach is used to generalize the Cooper-Zare central-potential model to anionic states of any mixed character. In the limit of atomic-anion photodetachment, the model reproduces the Cooper-Zare formula. In the case of an initial orbital described as a superposition of s and p-type functions, the model yields the previously obtained s-p mixing formula. The formalism is further advanced using the Hanstorp approximation, whereas the relative scaling of the partial-wave cross-sections is assumed to follow the Wigner threshold law. The resulting model describes the energy dependence of photoelectron anisotropy for any atomic, molecular, or cluster anions, usually without requiring a direct calculation of the transition dipole matrix elements. As a benchmark case, we apply the p-d variant of the model to the experimental results for NO(-) photodetachment and show that the observed anisotropy trend is described well using physically meaningful values of the model parameters. Overall, the presented formalism delivers insight into the photodetachment process and affords a new quantitative strategy for analyzing the photoelectron angular distributions and characterizing mixed-character molecular orbitals using photoelectron imaging spectroscopy of negative ions.

  10. Controlling the Charge State and Redox Properties of Supported Polyoxometalates via Soft Landing of Mass Selected Ions

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gunaratne, Kalupathirannehelage Don D.; Johnson, Grant E.; Andersen, Amity

    2014-12-04

    We investigate the controlled deposition of Keggin polyoxometalate (POM) anions, PMo12O403- and PMo12O402-, onto different self-assembled monolayer (SAM) surfaces via soft landing of mass-selected ions. Utilizing in situ infrared reflection absorption spectroscopy (IRRAS), ex situ cyclic voltammetry (CV) and electronic structure calculations, we examine the structure and charge retention of supported multiply-charged POM anions and characterize the redox properties of the modified surfaces. SAMs of alkylthiol (HSAM), perfluorinated alkylthiol (FSAM), and alkylthiol terminated with NH3+ functional groups (NH3+SAM) are chosen as model substrates for soft landing to examine the factors which influence the immobilization and charge retention of multiply chargedmore » anionic molecules. The distribution of charge states of POMs on different SAM surfaces are determined by comparing the IRRAS spectra with vibrational spectra calculated using density functional theory (DFT). In contrast to the results obtained previously for multiply charged cations, soft landed anions are found to retain charge on all three SAM surfaces. This charge retention is attributed to the substantial electron binding energy of the POM anions. Investigation of redox properties by CV reveals that, while surfaces prepared by soft landing exhibit similar features to those prepared by adsorption of POM from solution, the soft landed POM2- has a pronounced shift in oxidation potential compared to POM3- for one of the redox couples. These results demonstrate that ion soft landing is uniquely suited for precisely controlled preparation of substrates with specific electronic and chemical properties that cannot be achieved using conventional deposition techniques.« less

  11. The AHA Moment: Assessment of the Redox Stability of Ionic Liquids Based on Aromatic Heterocyclic Anions (AHAs) for Nuclear Separations and Electric Energy Storage.

    PubMed

    Shkrob, Ilya A; Marin, Timothy W

    2015-11-19

    Because of their extended conjugated bond network, aromatic compounds generally have higher redox stability than less saturated compounds. We conjectured that ionic liquids (ILs) consisting of aromatic heterocyclic anions (AHAs) may exhibit improved radiation and electrochemical stability. Such properties are important in applications of these ILs as diluents in radionuclide separations and electrolytes in the electric energy storage devices. In this study, we systematically examine the redox chemistry of the AHAs. Three classes of these anions have been studied: (i) simple 5-atom ring AHAs, such as the pyrazolide and triazolides, (ii) AHAs containing an adjacent benzene ring, and (iii) AHAs containing electron-withdrawing groups that were introduced to reduce their basicity and interaction with metal ions. It is shown that fragmentation in the reduced and oxidized states of these AHAs does not generally occur, and the two main products, respectively, are the H atom adduct and the imidyl radical. The latter species occurs either as an N σ-radical or as an N π-radical, depending on the length of the N-N bond, and the state that is stabilized in the solid matrix is frequently different from that having the lowest energy in the gas phase. In some instances, the formation of the sandwich π-stack dimer radical anions has been observed. For trifluoromethylated anions, H adduct formation did not occur; instead, there was facile loss of fluoride from their fluorinated groups. The latter can be problematic in nuclear separations, but beneficial in batteries. Overall, our study suggests that AHA-based ILs are viable candidates for use as radiation-exposed diluents and electrolytes.

  12. High-Tc superconductivity near the anion height instability in Fe-based superconductors: analysis of LaFeAsO(1-x)H(x).

    PubMed

    Onari, Seiichiro; Yamakawa, Youichi; Kontani, Hiroshi

    2014-05-09

    The isostructural transition in the tetragonal phase with a sizable change in the anion height, is realized in heavily H-doped LaFeAsO and (La,P) codoped CaFe2As2. In these compounds, the superconductivity with higher Tc (40-50 K) is realized near the isostructural transition. To find the origin of the anion-height instability and the role in realizing the higher-Tc state, we develop the orbital-spin fluctuation theory by including the vertex correction. We analyze LaFeAsO(1-x)H(x) and find that the non-nematic orbital fluctuations, which induce the anion-height instability, are automatically obtained at x∼0.5, in addition to the conventional nematic orbital fluctuations at x∼0. The non-nematic orbital order triggers the isostructural transition, and its fluctuation would be a key ingredient to realize higher-Tc superconductivity of order 50 K.

  13. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Trump, Benjamin A., E-mail: btrump1@jhu.edu; Department of Physics and Astronomy, Institute for Quantum Matter, Johns Hopkins University, Baltimore, MD 21218; McQueen, Tyrel M., E-mail: mcqueen@jhu.edu

    The synthesis and physical properties of the new distorted-Hollandite PbIr{sub 4}Se{sub 8} are reported. Powder X-ray diffraction and transmission electron microscopy show that the structure consists of edge- and corner-sharing IrSe{sub 6} octahedra, with one-dimensional channels occupied by Pb. The structure contains Se-Se anion-anion bonding, leading to an electron count of Pb{sup 2+}(Ir{sup 3+}){sub 4}(Se{sub 2}){sup 2-}(Se{sup 2−}){sub 6}, confirmed by bond-valence sums and diamagnetic behavior. Structural and heat capacity measurements demonstrate disorder on the Pb site, due to the combination of lone-pair effects and the large size of the one-dimensional channels. Comparisons are made to known Hollandite and pseudo-Hollanditemore » structures, which demonstrates that the anion-anion bonding in PbIr{sub 4}Se{sub 8} distorts its structure, to accommodate the Ir{sup 3+} state. An electronic structure calculation indicates semiconductor character with a band gap of 0.76(11) eV.« less

  14. Role of Electron-Driven Proton-Transfer Processes in the Ultrafast Deactivation of Photoexcited Anionic 8-oxoGuanine-Adenine and 8-oxoGuanine-Cytosine Base Pairs.

    PubMed

    Wu, Xiuxiu; Karsili, Tolga N V; Domcke, Wolfgang

    2017-01-14

    It has been reported that 8-oxo-7,8-dihydro-guanosine (8-oxo-G), which is the main product of oxidative damage of DNA, can repair cyclobutane pyrimidine dimer (CPD) lesions when incorporated into DNA or RNA strands in proximity to such lesions. It has therefore been suggested that the 8-oxo-G nucleoside may have been a primordial precursor of present-day flavins in DNA or RNA repair. Because the electron transfer leading to the splitting of a thymine-thymine pair in a CPD lesion occurs in the photoexcited state, a reasonably long excited-state lifetime of 8-oxo-G is required. The neutral (protonated) form of 8-oxo-G exhibits a very short (sub-picosecond) intrinsic excited-state lifetime which is unfavorable for repair. It has therefore been argued that the anionic (deprotonated) form of 8-oxo-G, which exhibits a much longer excited-state lifetime, is more likely to be a suitable cofactor for DNA repair. Herein, we have investigated the exited-state quenching mechanisms in the hydrogen-bonded complexes of deprotonated 8-oxo-G - with adenine (A) and cytosine (C) using ab initio wave-function-based electronic-structure calculations. The calculated reaction paths and potential-energy profiles reveal the existence of barrierless electron-driven inter-base proton-transfer reactions which lead to low-lying S₁/S₀ conical intersections. The latter can promote ultrafast excited-state deactivation of the anionic base pairs. While the isolated deprotonated 8-oxo-G - nucleoside may have been an efficient primordial repair cofactor, the excited states of the 8-oxo-G - -A and 8-oxo-G - -C base pairs are likely too short-lived to be efficient electron-transfer repair agents.

  15. Gas-phase synthesis of singly and multiply charged polyoxovanadate anions employing electrospray ionization and collision induced dissociation.

    PubMed

    Al Hasan, Naila M; Johnson, Grant E; Laskin, Julia

    2013-09-01

    Electrospray ionization mass spectrometry (ESI-MS) combined with in-source fragmentation and tandem mass spectrometry (MS/MS) experiments were used to generate a wide range of singly and multiply charged vanadium oxide cluster anions including VxOy(n-) and VxOyCl(n-) ions (x = 1-14, y = 2-36, n = 1-3), protonated clusters, and ligand-bound polyoxovanadate anions. The cluster anions were produced by electrospraying a solution of tetradecavanadate, V14O36Cl(L)5 (L = Et4N(+), tetraethylammonium), in acetonitrile. Under mild source conditions, ESI-MS generates a distribution of doubly and triply charged VxOyCl(n-) and VxOyCl(L)((n-1)-) clusters predominantly containing 14 vanadium atoms as well as their protonated analogs. Accurate mass measurement using a high-resolution LTQ/Orbitrap mass spectrometer (m/Δm = 60,000 at m/z 410) enabled unambiguous assignment of the elemental composition of the majority of peaks in the ESI-MS spectrum. In addition, high-sensitivity mass spectrometry allowed the charge state of the cluster ions to be assigned based on the separation of the major from the much less abundant minor isotope of vanadium. In-source fragmentation resulted in facile formation of smaller VxOyCl((1-2)-) and VxOy ((1-2)-) anions. Collision-induced dissociation (CID) experiments enabled systematic study of the gas-phase fragmentation pathways of the cluster anions originating from solution and from in-source CID. Surprisingly simple fragmentation patterns were obtained for all singly and doubly charged VxOyCl and VxOy species generated through multiple MS/MS experiments. In contrast, cluster anions originating directly from solution produced comparatively complex CID spectra. These results are consistent with the formation of more stable structures of VxOyCl and VxOy anions through low-energy CID. Furthermore, our results demonstrate that solution-phase synthesis of one precursor cluster anion combined with gas-phase CID is an efficient approach for the top-down synthesis of a wide range of singly and multiply charged gas-phase metal oxide cluster anions for subsequent investigations of structure and reactivity using mass spectrometry and ion spectroscopy techniques.

  16. Gas-Phase Synthesis of Singly and Multiply Charged Polyoxovanadate Anions Employing Electrospray Ionization and Collision Induced Dissociation

    NASA Astrophysics Data System (ADS)

    Al Hasan, Naila M.; Johnson, Grant E.; Laskin, Julia

    2013-09-01

    Electrospray ionization mass spectrometry (ESI-MS) combined with in-source fragmentation and tandem mass spectrometry (MS/MS) experiments were used to generate a wide range of singly and multiply charged vanadium oxide cluster anions including VxOy n- and VxOyCln- ions (x = 1-14, y = 2-36, n = 1-3), protonated clusters, and ligand-bound polyoxovanadate anions. The cluster anions were produced by electrospraying a solution of tetradecavanadate, V14O36Cl(L)5 (L = Et4N+, tetraethylammonium), in acetonitrile. Under mild source conditions, ESI-MS generates a distribution of doubly and triply charged VxOyCln- and VxOyCl(L)(n-1)- clusters predominantly containing 14 vanadium atoms as well as their protonated analogs. Accurate mass measurement using a high-resolution LTQ/Orbitrap mass spectrometer (m/Δm = 60,000 at m/z 410) enabled unambiguous assignment of the elemental composition of the majority of peaks in the ESI-MS spectrum. In addition, high-sensitivity mass spectrometry allowed the charge state of the cluster ions to be assigned based on the separation of the major from the much less abundant minor isotope of vanadium. In-source fragmentation resulted in facile formation of smaller VxOyCl(1-2)- and VxOy (1-2)- anions. Collision-induced dissociation (CID) experiments enabled systematic study of the gas-phase fragmentation pathways of the cluster anions originating from solution and from in-source CID. Surprisingly simple fragmentation patterns were obtained for all singly and doubly charged VxOyCl and VxOy species generated through multiple MS/MS experiments. In contrast, cluster anions originating directly from solution produced comparatively complex CID spectra. These results are consistent with the formation of more stable structures of VxOyCl and VxOy anions through low-energy CID. Furthermore, our results demonstrate that solution-phase synthesis of one precursor cluster anion combined with gas-phase CID is an efficient approach for the top-down synthesis of a wide range of singly and multiply charged gas-phase metal oxide cluster anions for subsequent investigations of structure and reactivity using mass spectrometry and ion spectroscopy techniques.

  17. Photoelectron spectrum of valence anions of uracil and first-principles calculations of excess electron binding energies.

    PubMed

    Bachorz, Rafał A; Klopper, Wim; Gutowski, Maciej; Li, Xiang; Bowen, Kit H

    2008-08-07

    The photoelectron spectrum (PES) of the uracil anion is reported and discussed from the perspective of quantum chemical calculations of the vertical detachment energies (VDEs) of the anions of various tautomers of uracil. The PES peak maximum is found at an electron binding energy of 2.4 eV, and the width of the main feature suggests that the parent anions are in a valence rather than a dipole-bound state. The canonical tautomer as well as four tautomers that result from proton transfer from an NH group to a C atom were investigated computationally. At the Hartree-Fock and second-order Moller-Plesset perturbation theory levels, the adiabatic electron affinity (AEA) and the VDE have been converged to the limit of a complete basis set to within +/-1 meV. Post-MP2 electron-correlation effects have been determined at the coupled-cluster level of theory including single, double, and noniterative triple excitations. The quantum chemical calculations suggest that the most stable valence anion of uracil is the anion of a tautomer that results from a proton transfer from N1H to C5. It is characterized by an AEA of 135 meV and a VDE of 1.38 eV. The peak maximum is as much as 1 eV larger, however, and the photoelectron intensity is only very weak at 1.38 eV. The PES does not lend support either to the valence anion of the canonical tautomer, which is the second most stable anion, and whose VDE is computed at about 0.60 eV. Agreement between the peak maximum and the computed VDE is only found for the third most stable tautomer, which shows an AEA of approximately -0.1 eV and a VDE of 2.58 eV. This tautomer results from a proton transfer from N3H to C5. The results illustrate that the characteristics of biomolecular anions are highly dependent on their tautomeric form. If indeed the third most stable anion is observed in the experiment, then it remains an open question why and how this species is formed under the given conditions.

  18. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hou, Gao-Lei; Wang, Xue-Bin; McCoy, Anne B.

    The transition-state (TS) region of the simplest heavy-light-heavy type of reaction, F• + H-F F-H + F•, is investigated in this work by a joint experimental and theoretical approach. Photodetaching the bifluride anion, [F…H…F]–, generates a negative ion photoelectron (NIPE) spectrum with three partially resolved bands in the electron binding energy (eBE) range of 5.4 – 7.0 eV. These bands correspond to the transition from the ground state of the anion to the electronic ground state of [F-H-F]• neutral, with associated vibrational excitations. The significant increase of eBE of the bifluride anion, relative to that of F-, reflects a hydrogenmore » bond energy between F- and HF of 46 kcal/mol. Theoretical modeling reveals that the antisymmetric motion of H between the two F atoms, near the TS on the neutral [F-H-F]• surface, dominates the observed three bands, while the F-H-F bending, F—F symmetric stretching modes, and the couplings between them is calculated to account for the breadth of the observed spectrum. From the NIPE spectrum, a lower limit on the activation enthalpy for F• + H-F F-H + F can be estimated to be H‡ = 12 ± 2 kcal/mol, a value below that of H‡ = 14.9 kcal/mol, given by our G4 calculations.« less

  19. 77 FR 54647 - Culturally Significant Objects Imported for Exhibition Determinations: “Manet: Portraying Life”

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-05

    ... DEPARTMENT OF STATE [Public Notice 8012] Culturally Significant Objects Imported for Exhibition Determinations: ``Manet: Portraying Life'' SUMMARY: Notice is hereby given of the following determinations...: Portraying Life,'' imported from abroad for temporary exhibition within the United States, are of cultural...

  20. 75 FR 23318 - Culturally Significant Objects Imported for Exhibition Determinations: “John Baldessari: Pure...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-03

    ... DEPARTMENT OF STATE [Public Notice 6983] Culturally Significant Objects Imported for Exhibition Determinations: ``John Baldessari: Pure Beauty'' SUMMARY: Notice is hereby given of the following determinations... Baldessari: Pure Beauty,'' imported from abroad for temporary exhibition within the United States, are of...

  1. 75 FR 27613 - Culturally Significant Objects Imported for Exhibition Determinations: “The Holocaust (Warsaw...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-17

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    Federal Register 2010, 2011, 2012, 2013, 2014

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  3. 20 CFR 655.50 - Enforcement process.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

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    Federal Register 2010, 2011, 2012, 2013, 2014

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    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-22

    ... DEPARTMENT OF STATE [Public Notice 8249] Culturally Significant Objects Imported for Exhibition Determinations: ``Maya: Hidden Worlds Revealed'' SUMMARY: Notice is hereby given of the following determinations... Worlds Revealed,'' imported from abroad for temporary exhibition within the United States, are of...

  6. Deployment Efficiency and Barrier Effectiveness Testing of a Temporary Anti-Personnel (TAP) Barrier System.

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Allen, David James; Hedrick, Charles D.; Martinez, Ruben

    This report documents tests conducted by Sandia National Laboratories (SNL) on behalf of the U.S. Department of State to evaluate a temporary anti-personnel (TAP) barrier system developed by Mitigation Technologies. For this, the SNL Denial and Structural Assessment department developed a test protocol for the evaluation of the TAP barrier system on the basis of deployment efficiency and barrier effectiveness against a riotous/mob attack threat. The test protocol was then executed by SNL personnel and the results of the testing are documented.

  7. Probing the intrinsic electronic structure of the bis(dithiolene) anions [M(mnt)2]2- and [M(mnt)2]1- (M = Ni, Pd, Pt; mnt = 1,2-S2C2(CN)2) in the gas phase by photoelectron spectroscopy.

    PubMed

    Waters, Tom; Woo, Hin-Koon; Wang, Xue-Bin; Wang, Lai-Sheng

    2006-04-05

    A detailed understanding of the electronic structure of transition metal bis(dithiolene) complexes is important because of their interesting redox, magnetic, optical, and conducting properties and their relevance to enzymes containing molybdenum and tungsten bis(dithiolene) centers. The electronic structures of the bis(dithiolene) anions [M(mnt)(2)](n-) (M = Ni, Pd, Pt; mnt = 1,2-S(2)C(2)(CN)(2); n = 0-2) were examined by a combination of photodetachment photoelectron spectroscopy (PES) and density functional theory calculations. The combined experimental and theoretical data provide insight into the molecular orbital energy levels of [M(mnt)(2)](2-) and the ground and excited states of [M(mnt)(2)](1-) and [M(mnt)(2)]. Detachment features from ligand-based orbitals of [M(mnt)(2)](2-) occur at similar energies for each species, independent of the metal center, while those arising from metal-based orbitals occur at higher energies for the heavier congeners. Electronic excitation energies inferred for [M(mnt)(2)](1-) from the PES experiments agree well with those obtained in optical absorption experiments in solution, with the PES experiments providing additional insight into the changes in energy of these transitions as a function of metal. The singly charged anions [M(mnt)(2)](1-) were also prepared and studied independently. Electron detachment from the ground states of these doublet anions accessed the lowest singlet and triplet states of neutral [M(mnt)(2)], thereby providing a direct experimental measure of their singlet-triplet splitting.

  8. Texas Red transport across rat and dogfish shark (Squalus acanthias) choroid plexus

    PubMed Central

    Reichel, Valeska; Miller, David S.; Fricker, Gert

    2008-01-01

    Confocal microscopy and image analysis were used to compare driving forces, specificity, and regulation of transport of the fluorescent organic anion, Texas Red (sulforhodamine 101 free acid; TR), in lateral choroid plexus (CP) isolated from rat and an evolutionarily ancient vertebrate, dogfish shark (Squalus acanthias). CP from both species exhibited concentrative, specific, and metabolism-dependent TR transport from bath to subepithelial/vascular space; at steady state, TR accumulation in vascular/subepithelial space was substantially higher than in epithelial cells. In rat CP, steady-state TR accumulation in subepithelial/vascular spaces was reduced by Na+-replacement, but was not affected by a 10-fold increase in buffer K+. In shark CP, Na+-replacement did not alter TR accumulation in either tissue compartment; subepithelial/vascular space levels of TR were reduced in high-K+ medium. In both species, steady-state TR accumulation was not affected by p-aminohippurate or leukotriene C4, suggesting that neither organic anion transporters (SLC22A family) nor multidrug resistance-associated proteins (ABCC family) contributed. In rat CP, digoxin was without effect, indicating that organic anion transporting polypeptide isoform 2 was not involved. Several organic anions reduced cellular and subepithelial/vascular space TR accumulation in both tissues, including estrone sulfate, taurocholate, and the Mrp1 inhibitor MK571. In rat CP, TR accumulation in subepithelial/vascular spaces increased with PKA activation (forskolin), but was not affected by PKC activation (phorbol ester). In shark, neither PKA nor PKC activation specifically affected TR transport. Thus, rat and dogfish shark CP transport TR but do so using different basic mechanisms that respond to different regulatory signals. PMID:18650317

  9. Charge retention of soft-landed phosphotungstate Keggin anions on self-assembled monolayers

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gunaratne, K. Don D.; Prabhakaran, Venkateshkumar; Andersen, Amity

    Soft landing of mass-selected ions onto surfaces often results in partial loss of charge that may affect the structure and reactivity of deposited species. In this study, Keggin phosphotungstate anions in two selected charge states, PW12O403- (WPOM3-) and PW12O402- (WPOM2-), were soft-landed onto different self-assembled monolayer (SAM) surfaces and examined using in situ infrared reflection absorption spectroscopy (IRRAS) and density functional theory (DFT) calculations. Partial retention of the 3- charge was observed when WPOM3- was soft-landed onto the fluorinated SAM (FSAM), while the charge state distribution was dominated by the 2- charge after both WPOM3- and WPOM2- were deposited ontomore » a hydrophilic alkylthiol SAM terminated with cationic NH3+ functional groups (NH3+SAM). We found that during the course of the soft landing of WPOM3-, the relative abundance of WPOM3- on FSAM decreased while that of WPOM2- increased. We propose that the higher stability of immobilized WPOM2- in comparison with WPOM3- makes it the preferred charge state of WPOM on both the FSAM and NH3+SAM. We also observe weaker binding of WPOM anions to SAMs in comparison with phosphomolybdate ions (MoPOM) reported previously (J. Phys. Chem. C 2014, 118, 27611–27622). The weaker binding of WPOM to SAMs is attributed to the lower reactivity of WPOM reported in the literature. This study demonstrates that both the charge retention and the reactivity of deposited anionic POM clusters on surfaces are determined by the type of addenda metal atoms in the cluster.« less

  10. Theoretical calculations on the electron absorption spectra of selected Polycyclic Aromatic Hydrocarbons (PAH) and derivatives

    NASA Technical Reports Server (NTRS)

    Du, Ping

    1993-01-01

    As a theoretical component of the joint effort with the laboratory of Dr. Lou Allamandola to search for potential candidates for interstellar organic carbon compound that are responsible for the visible diffuse interstellar absorption bands (DIB's), quantum mechanical calculations were performed on the electron absorption spectra of selected polycyclic aromatic hydrocarbons (PAH) and derivatives. In the completed project, 15 different species of naphthalene, its hydrogen abstraction and addition derivatives, and corresponding cations and anions were studied. Using semiempirical quantum mechanical method INDO/S, the ground electronic state of each species was evaluated with restricted Hartree-Fock scheme and limited configuration interaction. The lowest energy spin state for each species was used for electron absorption calculations. Results indicate that these calculations are accurate enough to reproduce the spectra of naphthalene cation and anion observed in neon matrix. The spectral pattern of the hydrogen abstraction and addition derivatives predicted based on these results indicate that the electron configuration of the pi orbitals of these species is the dominant determinant. A combined list of 19 absorptions calculated from 4500 A to 10,400 A were compiled and suggested as potential candidates that are relevant for the DIB's absorptions. Continued studies on pyrene and derivatives revealed the ground state symmetries and multiplicities of its neutral, anionic, and cationic species. Spectral calculations show that the cation (B(sub 3g)-2) and the anion (A(sub u)-2) are more likely to have low energy absorptions in the regions between 10 kK and 20 kK, similar to naphthalene. These absorptions, together with those to be determined from the hydrogen abstraction and addition derivatives of pyrene, can be used to provide additional candidates and suggest experimental work in the search for interstellar compounds that are responsible for DIB's.

  11. Relying on the National Mobile Disaster Hospital as a business continuity strategy in the aftermath of a tornado: The Louisville experience.

    PubMed

    Kearns, Randy D; Stringer, Lew; Craig, James; Godette-Crawford, Regina; Black, Paul S; Andra, David L; Winslow, James

    2017-01-01

    On 28th April, 2014, a tornado left much of Louisville, MS and the local hospital, Winston Medical Center, in ruin. In the USA, temporary hospital solutions have been used to augment the mainstream healthcare system since the American Civil War. As memories fade, however, the necessary readiness for a temporary hospital also fades, at times leaving a patchwork of resources either underfunded or abandoned. With the creation of the Hospital Preparedness Program, several temporary hospital solutions were created in various states across the USA. In the present case, Mississippi and North Carolina resources were used in Louisville in the aftermath of a direct impact that destroyed the hospital and nursing home. In the hours that followed, after lives were saved and patients safely relocated, a frank assessment confirmed the structural loss of the hospital. Local emergency responders, hospital staff, state and federal representatives all rallied with the aim of saving the community's only hospital. The steps taken in Louisville and the deliberate restoration of these essential services offer a learning opportunity for all involved in healthcare disaster preparedness, response and recovery.

  12. Law Enforcement and Gun Retailers as Partners for Safely Storing Guns to Prevent Suicide: A Study in 8 Mountain West States.

    PubMed

    Runyan, Carol W; Brooks-Russell, Ashley; Brandspigel, Sara; Betz, Marian; Tung, Gregory; Novins, Douglas; Agans, Robert

    2017-11-01

    To examine the extent to which law enforcement agencies (LEAs) and gun retailers are willing to offer voluntary, temporary storage as a part of an overall suicide prevention effort. We invited all LEAs and gun retailers in 8 US states to respond to questionnaires asking about their willingness to offer temporary gun storage and their recommendations to gun owners about safe storage. We collected data in 2016 from 448 LEAs and 95 retailers (response rates of 53% and 25%, respectively). Three quarters of LEAs (74.8%; 95% confidence interval [CI] = 72.1, 77.5) indicated they already provided temporary storage compared with 47.6% (95% CI = 39.2, 56.0) of retailers. LEAs were most willing to provide storage when a gun owner was concerned about the mental health of a family member. Retailers were more receptive than were LEAs to providing storage when visitors were coming or for people wanting storage while traveling. Both groups recommended locking devices within the home, but LEAs were slightly more favorable to storing guns away from the home. Law enforcement agencies and gun retailers are important resources for families concerned about suicide.

  13. Intramolecular, Exciplex-Mediated, Proton-Coupled, Charge-Transfer Processes in N,N-Dimethyl-3-(1-pyrenyl)propan-1-ammonium Cations: Influence of Anion, Solvent Polarity, and Temperature.

    PubMed

    Safko, Trevor M; Faleiros, Marcelo M; Atvars, Teresa D Z; Weiss, Richard G

    2016-06-16

    An intramolecular exciplex-mediated, proton-coupled, charge-transfer (PCCT) process has been investigated for a series of N,N-dimethyl-3-(1-pyrenyl)propan-1-ammonium cations with different anions (PyS) in solvents of low to intermediate polarity over a wide temperature range. Solvent mediates both the equilibrium between conformations of the cation that place the pyrenyl and ammonium groups in proximity (conformation C) or far from each other (conformation O) and the ability of the ammonium group to transfer a proton adiabatically in the PyS excited singlet state. Thus, exciplex emission, concurrent with the PCCT process, was observed only in hydrogen-bond accepting solvents of relatively low polarity (tetrahydrofuran, ethyl acetate, and 1,4-dioxane) and not in dichloromethane. From the exciplex emission and other spectroscopic and thermodynamic data, the acidity of the ammonium group in conformation C of the excited singlet state of PyS (pKa*) has been estimated to be ca. -3.4 in tetrahydrofuran. The ratios between the intensities of emission from the exciplex and the locally excited state (IEx/ILE) appear to be much more dependent on the nature of the anion than are the rates of exciplex formation and decay, although the excited state data do not provide a quantitative measure of the anion effect on the C-O equilibrium. The activation energies associated with exciplex formation in THF are calculated to be 0.08 to 0.15 eV lower than for the neutral amine, N,N-dimethyl-3-(1-pyrenyl)propan-1-amine. Decay of the exciplexes formed from the deprotonation of PyS is hypothesized to occur through charge-recombination processes. To our knowledge, this is the first example in which photoacidity and intramolecular exciplex formation (i.e., a PCCT reaction) are coupled.

  14. Properties of the low-lying electronic states of phenanthrene: Exact PPP results

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chakrabarti, A.; Ramasesha, S.

    1996-10-05

    The authors report properties of the exact low-lying states of phenanthrene, its anion and dianion within the Pariser-Parr-Pople (PPP) model. The experimentally known singlet states of the neutral molecule are well reproduced by the model. The intensities for one and two photon absorption to various single states are also in good agreement with experiment. From the bond orders of these states, the authors predict the equilibrium geometries. The relaxation energies of these states, computed from charge-charge correlations and bond orders, are presented. The authors also present results of ring current calculations in the singlet ground state of phenanthrene. The authorsmore » have also reported energies, spin densities, bond orders, and relaxation energies of several triplet states and compared then with experiments as well as with other calculations, where available. The fine structure constants D and E, computed in the lowest triplet state, compare well with those obtained from experiments. These properties are also presented for the anions and the dianions. The PPP model in these cases predicts a low-energy (< 1 eV) dipole excitation. 31 refs., 4 figs., 9 tabs.« less

  15. United States Air Force Summer Faculty Research Program 1989. Program Technical Report. Volume 1

    DTIC Science & Technology

    1989-12-01

    Amy Miller Transition-Metal Compounds ; Reactions of Iron and Iron Carbonyl Anions 59 Acidities of Iron Hydride and Various Dr. Thomas Miller...Transition-Metal Compounds ; Reactions of Iron and Iron Carbonyl Anions (Same Report as Dr. Amy Miller) 60 C02(4.3pm) Vibrational Temperatures and Dr. Henry...Release. Table VIII gives data on the the two alloy systems, Pd/Al and Ni/Al. It also gives some properties of the compound , Pd/Hz. A brief description of

  16. An In Situ Directing Group Strategy for Chiral Anion Phase-Transfer Fluorination of Allylic Alcohols

    PubMed Central

    2015-01-01

    An enantioselective fluorination of allylic alcohols under chiral anion phase-transfer conditions is reported. The in situ generation of a directing group proved crucial for achieving effective enantiocontrol. In the presence of such a directing group, a range of acyclic substrates underwent fluorination to afford highly enantioenriched α-fluoro homoallylic alcohols. Mechanistic studies suggest that this transformation proceeds through a concerted enantiodetermining transition state involving both C–F bond formation and C–H bond cleavage. PMID:25203796

  17. Facile Conversion of Red Phosphorus into Soluble Polyphosphide Anions by Reaction with Potassium Ethoxide.

    PubMed

    Dragulescu-Andrasi, Alina; Miller, L Zane; Chen, Banghao; McQuade, D Tyler; Shatruk, Michael

    2016-03-14

    Soluble polyphosphide anions were successfully generated in a number of organic solvents by the reaction between shelf-stable red phosphorus and potassium ethoxide. The species were identified by (31)P NMR spectroscopy in solution and by X-ray crystal-structure determination of (Bu4N)2P16 in the solid state. The reaction was scaled up to gram quantities by using a flow-chemistry process. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. 20 CFR 655.25-655.29 - [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... EMPLOYMENT OF FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process and Enforcement of Attestations for Temporary Employment in Occupations Other Than Agriculture or Registered Nursing in the United...

  19. 20 CFR 655.65 - Remedies for violations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... EMPLOYMENT OF FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process and Enforcement of Attestations for Temporary Employment in Occupations Other Than Agriculture or Registered Nursing in the United...

  20. 20 CFR 655.70 - WHD Administrator's determination.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... EMPLOYMENT OF FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process and Enforcement of Attestations for Temporary Employment in Occupations Other Than Agriculture or Registered Nursing in the United...

  1. 20 CFR 655.12-655.14 - [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... EMPLOYMENT OF FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process and Enforcement of Attestations for Temporary Employment in Occupations Other Than Agriculture or Registered Nursing in the United...

  2. 20 CFR 655.32 - Labor certification determinations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... EMPLOYMENT OF FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process and Enforcement of Attestations for Temporary Employment in Occupations Other Than Agriculture or Registered Nursing in the United...

  3. 20 CFR 655.18-655.19 - [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... EMPLOYMENT OF FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process and Enforcement of Attestations for Temporary Employment in Occupations Other Than Agriculture or Registered Nursing in the United...

  4. Environment and initial state engineered dynamics of quantum and classical correlations

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wang, Cheng-Zhi, E-mail: czczwang@outlook.com; Li, Chun-Xian; Guo, Yu

    Based on an open exactly solvable system coupled to an environment with nontrivial spectral density, we connect the features of quantum and classical correlations with some features of the environment, initial states of the system, and the presence of initial system–environment correlations. Some interesting features not revealed before are observed by changing the structure of environment, the initial states of system, and the presence of initial system–environment correlations. The main results are as follows. (1) Quantum correlations exhibit temporary freezing and permanent freezing even at high temperature of the environment, for which the necessary and sufficient conditions are given bymore » three propositions. (2) Quantum correlations display a transition from temporary freezing to permanent freezing by changing the structure of environment. (3) Quantum correlations can be enhanced all the time, for which the condition is put forward. (4) The one-to-one dependency relationship between all kinds of dynamic behaviors of quantum correlations and the initial states of the system as well as environment structure is established. (5) In the presence of initial system–environment correlations, quantum correlations under local environment exhibit temporary multi-freezing phenomenon. While under global environment they oscillate, revive, and damp, an explanation for which is given. - Highlights: • Various interesting behaviors of quantum and classical correlations are observed in an open exactly solvable model. • The important effects of the bath structure on quantum and classical correlations are revealed. • The one-to-one correspondence between the type of dynamical behavior of quantum discord and the initial state is given. • Quantum correlations are given in the presence of initial qubits–bath correlations.« less

  5. 75 FR 25031 - Culturally Significant Objects Imported for Exhibition Determinations: “Tiffany: Color and Light”

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-06

    ... DEPARTMENT OF STATE [Public Notice 6987] Culturally Significant Objects Imported for Exhibition Determinations: ``Tiffany: Color and Light'' SUMMARY: Notice is hereby given of the following determinations...: Color and Light,'' imported from abroad for temporary exhibition within the United States, is of...

  6. 26 CFR 1.956-3T - Certain trade or service receivables acquired from United States persons (temporary).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... investment in United States property by the seller's controlled foreign corporation, unless it can be... SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Controlled Foreign... foreign corporation has acquired a trade or service receivable. (2) Indirect acquisitions—(i) Acquisition...

  7. 77 FR 52783 - Culturally Significant Objects Imported for Exhibition Determinations: “Rudolf Nureyev: A Life in...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-30

    ... DEPARTMENT OF STATE [Public Notice 8003] Culturally Significant Objects Imported for Exhibition Determinations: ``Rudolf Nureyev: A Life in Dance'' SUMMARY: Notice is hereby given of the following... ``Rudolf Nureyev: A Life in Dance'' imported from abroad for temporary exhibition within the United States...

  8. Assessing STD Partner Services in State and Local Health Departments.

    PubMed

    Cuffe, Kendra M; Leichliter, Jami S; Gift, Thomas L

    2018-02-07

    State and local health department STD programs provide several partner services to reduce disease transmission. Budget cuts and temporary staff reassignments for public health emergencies may affect the provision of partner services. Determining the impact of staffing reductions on STD rates and public health response should be further assessed.

  9. 20 CFR 655.31 - Debarment.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... WORKERS IN THE UNITED STATES Labor Certification Process and Enforcement of Attestations for Temporary Employment in Occupations Other Than Agriculture or Registered Nursing in the United States (H-2B Workers... a significant failure to comply with the RFI or audit process pursuant to §§ 655.23 or 655.24; (v...

  10. 20 CFR 655.75 - Decision and order of administrative law judge.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... LABOR TEMPORARY EMPLOYMENT OF FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process and... Nursing in the United States (H-2B Workers) § 655.75 Decision and order of administrative law judge. (a... determination resulting from that process. Under no circumstances shall the administrative law judge determine...

  11. 78 FR 62326 - Culturally Significant Objects Imported for Exhibition Determinations: “Toulouse-Lautrec and La...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-16

    ... DEPARTMENT OF STATE [Public Notice 8500] Culturally Significant Objects Imported for Exhibition Determinations: ``Toulouse-Lautrec and La Vie Moderne: Paris 1880- 1910'' SUMMARY: Notice is hereby given of the...: Paris 1880-1910,'' imported from abroad for temporary exhibition within the United States, are of...

  12. 76 FR 42158 - Culturally Significant Objects Imported for Exhibition Determinations: “Rembrandt and the Face of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-18

    ... DEPARTMENT OF STATE [Public Notice: 7526] Culturally Significant Objects Imported for Exhibition Determinations: ``Rembrandt and the Face of Jesus'' SUMMARY: Notice is hereby given of the following... ``Rembrandt and the Face of Jesus,'' imported from abroad for temporary exhibition within the United States...

  13. 76 FR 63702 - Culturally Significant Objects Imported for Exhibition Determinations: “Aphrodite and the Gods of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-13

    ... DEPARTMENT OF STATE [Public Notice: 7645] Culturally Significant Objects Imported for Exhibition Determinations: ``Aphrodite and the Gods of Love'' SUMMARY: Notice is hereby given of the following... ``Aphrodite and the Gods of Love,'' imported from abroad for temporary exhibition within the United States...

  14. 77 FR 46146 - Culturally Significant Objects Imported for Exhibition Determinations: “Shock of the News”

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-02

    ... DEPARTMENT OF STATE [Public Notice 7967] Culturally Significant Objects Imported for Exhibition Determinations: ``Shock of the News'' SUMMARY: Notice is hereby given of the following determinations: Pursuant... News,'' imported from abroad for temporary exhibition within the United States, are of cultural...

  15. 78 FR 18664 - Culturally Significant Objects Imported for Exhibition Determinations: “Diaghilev and the Ballets...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-27

    ... DEPARTMENT OF STATE [Public Notice 8259] Culturally Significant Objects Imported for Exhibition Determinations: ``Diaghilev and the Ballets Russes, 1909-1929: When Art Danced With Music'' SUMMARY: Notice is... with Music,'' imported from abroad for temporary exhibition within the United States, are of cultural...

  16. 78 FR 59080 - Culturally Significant Objects Imported for Exhibition Determinations: “Delacroix and the Matter...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-25

    ... DEPARTMENT OF STATE [Public Notice 8482] Culturally Significant Objects Imported for Exhibition Determinations: ``Delacroix and the Matter of Finish'' SUMMARY: Notice is hereby given of the following... ``Delacroix and the Matter of Finish,'' imported from abroad for temporary exhibition within the United States...

  17. 76 FR 56865 - Culturally Significant Objects Imported for Exhibition Determinations: “Degas and the Nude”

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-14

    ... DEPARTMENT OF STATE [Public Notice 7584] Culturally Significant Objects Imported for Exhibition Determinations: ``Degas and the Nude'' SUMMARY: Notice is hereby given of the following determinations: Pursuant... Nude,'' imported from abroad for temporary exhibition within the United States, are of cultural...

  18. 77 FR 31421 - Culturally Significant Objects Imported for Exhibition Determinations: “Portrait of Helena de Kay”

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-25

    ... DEPARTMENT OF STATE [Public Notice 7896] Culturally Significant Objects Imported for Exhibition Determinations: ``Portrait of Helena de Kay'' SUMMARY: Notice is hereby given of the following determinations... Helena de Kay,'' imported from abroad for temporary exhibition within the United States, is of cultural...

  19. 75 FR 54691 - Culturally Significant Objects Imported for Exhibition Determinations: “The Vorticists: Rebel...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-08

    ... DEPARTMENT OF STATE [Public Notice: 7154] Culturally Significant Objects Imported for Exhibition Determinations: ``The Vorticists: Rebel Artists in London and New York, 1914-18'' SUMMARY: Notice is hereby given... London and New York, 1914-18,'' imported from abroad for temporary exhibition within the United States...

  20. 77 FR 48199 - Culturally Significant Objects Imported for Exhibition Determinations: “Bernini: Sculpting in Clay”

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-13

    ... DEPARTMENT OF STATE [Public Notice 7978] Culturally Significant Objects Imported for Exhibition Determinations: ``Bernini: Sculpting in Clay'' SUMMARY: Notice is hereby given of the following determinations...: Sculpting in Clay,'' imported from abroad for temporary exhibition within the United States, are of cultural...

  1. 77 FR 61468 - Culturally Significant Objects Imported for Exhibition Determinations: “Balthus: Cats and Girls”

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-09

    ... DEPARTMENT OF STATE [Public Notice 8057] Culturally Significant Objects Imported for Exhibition Determinations: ``Balthus: Cats and Girls'' SUMMARY: Notice is hereby given of the following determinations... and Girls,'' imported from abroad for temporary exhibition within the United States, are of cultural...

  2. A 200-year perspective on alternative stable state theory and lake management from a biomanipulated shallow lake.

    PubMed

    Hobbs, William O; Hobbs, Joy M Ramstack; LaFrançois, Toben; Zimmer, Kyle D; Theissen, Kevin M; Edlund, Mark B; Michelutti, Neal; Butler, Malcolm G; Hanson, Mark A; Carlson, Thomas J

    2012-07-01

    Multiple stressors to a shallow lake ecosystem have the ability to control the relative stability of alternative states (clear, macrophyte-dominated or turbid, algal-dominated). As a consequence, the use of remedial biomanipulations to induce trophic cascades and shift a turbid lake to a clear state is often only a temporary solution. Here we show the instability of short-term manipulations in the shallow Lake Christina (Minnesota, USA) is governed by the long-term state following a regime shift in the lake. During the modern, managed period of the lake, three top-down manipulations (fish kills) were undertaken inducing temporary (5-10 years) unstable clear-water states. Paleoecological remains of diatoms, along with proxies of primary production (total chlorophyll a and total organic carbon accumulation rate) and trophic state (total P) from sediment records clearly show a single regime shift in the lake during the early 1950s; following this shift, the functioning of the lake ecosystem is dominated by a persistent turbid state. We find that multiple stressors contributed to the regime shift. First, the lake began to eutrophy (from agricultural land use and/or increased waterfowl populations), leading to a dramatic increase in primary production. Soon after, the construction of a dam in 1936 effectively doubled the depth of the lake, compounded by increases in regional humidity; this resulted in an increase in planktivorous and benthivorous fish reducing phytoplankton grazers. These factors further conspired to increase the stability of a turbid regime during the modern managed period, such that switches to a clear-water state were inherently unstable and the lake consistently returned to a turbid state. We conclude that while top-down manipulations have had measurable impacts on the lake state, they have not been effective in providing a return to an ecosystem similar to the stable historical period. Our work offers an example of a well-studied ecosystem forced by multiple stressors into a new long-term managed period, where manipulated clear-water states are temporary, managed features.

  3. NO3- anions can act as Lewis acid in the solid state

    NASA Astrophysics Data System (ADS)

    Bauzá, Antonio; Frontera, Antonio; Mooibroek, Tiddo J.

    2017-02-01

    Identifying electron donating and accepting moieties is crucial to understanding molecular aggregation, which is of pivotal significance to biology. Anions such as NO3- are typical electron donors. However, computations predict that the charge distribution of NO3- is anisotropic and minimal on nitrogen. Here we show that when the nitrate's charge is sufficiently dampened by resonating over a larger area, a Lewis acidic site emerges on nitrogen that can interact favourably with electron rich partners. Surveys of the Cambridge Structural Database and Protein Data Bank reveal geometric preferences of some oxygen and sulfur containing entities around a nitrate anion that are consistent with this `π-hole bonding' geometry. Computations reveal donor-acceptor orbital interactions that confirm the counterintuitive Lewis π-acidity of nitrate.

  4. Specific anions effects of on the stability of azurin in ice.

    PubMed

    Strambini, Giovanni B; Gonnelli, Margherita

    2008-08-21

    This investigation represents a first attempt to gain a quantitative estimate of the effects of the anions sulfate, citrate, acetate, chloride and thiocyanate on the thermodynamic stability (DeltaG degrees) of a model globular protein in ice at -15 degrees C. The method, based on guanidinium chloride denaturation of the azurin mutant C112S from Pseudomonas aeruginosa, distinguishes between the effects of cooling to subfreezing temperatures from those induced specifically by the formation of a solid ice phase. The results confirm that, both in liquid and frozen states, kosmotropes (sulfate, citrate and acetate) increase significantly protein stability, relative to chloride, whereas the chaotrope thiocyanate decreases it. Throughout, their stabilizing efficacy was found to rank according to the Hofmeister series, sulfate>citrate>acetate>chloride>thiocyanate, although the magnitude of Delta(DeltaG degrees) exhibited a distinct sensitivity among the anions to low temperature and to ice formation. In the liquid state, lowering the temperature from +20 to -15 degreesC weakens considerably the stabilizing efficacy of the organic anions citrate and acetate. Among the anions sulfate stands out as the only strong stabilizer at subfreezing temperatures while SCN- becomes an even stronger denaturant. Freezing of the solution in the presence the "neutral" salt NaCl destabilizes the protein, DeltaG degrees progressively decreasing up to 3-4 kcal/mol as the fraction of liquid water in equilibrium with ice (VL) is reduced to less than 1%. Kosmotropes do attenuate the decrease in protein stability in ice although in the case of citrate and acetate, their efficacy diminishes sharply as the liquid fraction shrinks to below 2.7%. On the contrary, sulfate is remarkable for it maintains constantly high the stability of azurin in liquid and frozen solutions, down to the smallest VL (0.5%) examined. Throughout, the reduction in DeltaG degrees caused by the solidification of water correlates with the decrease in the denaturant m value, an indirect indication that protein-ice interactions generally lead to partial unfolding of the native state. It is proposed that binding of the kosmotropes to the ice interface may inhibit protein adsorption to the solid phase and thereby counter the ice perturbation.

  5. Seasonal and spatial variabilities in the water chemistry of prairie pothole wetlands influence the photoproduction of reactive intermediates.

    PubMed

    McCabe, Andrew J; Arnold, William A

    2016-07-01

    The hydrology and water chemistry of prairie pothole wetlands vary spatially and temporally, on annual and decadal timescales. Pesticide contamination of wetlands arising from agricultural activities is a foremost concern. Photochemical reactions are important in the natural attenuation of pesticides and may be important in limiting ecological and human exposure. Little is known, however, about the variable influence of wetland water chemistry on indirect photochemistry. In this study, seasonal water samples were collected from seven sites throughout the prairie pothole region over three years to understand the spatiotemporal dynamics of reactive intermediate photoproduction. Samples were classified by the season in which they were collected (spring, summer, or fall) and the typical hydroperiod of the wetland surface water (temporary or semi-permanent). Under photostable conditions, steady-state concentrations and apparent quantum yields or quantum yield coefficients were measured for triplet excited states of dissolved organic matter, singlet oxygen, hydroxyl radical, and carbonate radical under simulated sunlight. Steady-state concentrations and quantum yields increased on average by 15% and 40% from spring to fall, respectively. Temporary wetlands had 40% higher steady-state concentrations of reactive intermediates than semi-permanent wetlands, but 50% lower quantum yields. Computed quantum yields for reactive intermediate formation were used to predict the indirect photochemical half-lives of seven pesticides in average temporary and semi-permanent prairie pothole wetlands. As a first approximation, the predictions agree to within two orders of magnitude of previously reported half-lives. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Inelastic rate coefficients for collisions of C6H- with H2 and He

    NASA Astrophysics Data System (ADS)

    Walker, Kyle M.; Lique, François; Dumouchel, Fabien; Dawes, Richard

    2017-04-01

    The recent detection of anions in the interstellar medium has shown that they exist in a variety of astrophysical environments - circumstellar envelopes, cold dense molecular clouds and star-forming regions. Both radiative and collisional processes contribute to molecular excitation and de-excitation in these regions so that the 'local thermodynamic equilibrium' approximation, where collisions cause the gas to behave thermally, is not generally valid. Therefore, along with radiative coefficients, collisional excitation rate coefficients are needed to accurately model the anionic emission from these environments. We focus on the calculation of state-to-state rate coefficients of the C6H- molecule in its ground vibrational state in collisions with para-H2, ortho-H2 and He using new potential energy surfaces. Dynamical calculations for the pure rotational excitation of C6H- were performed for the first 11 rotational levels (up to j1 = 10) using the close-coupling method, while the coupled-states approximation was used to extend the H2 rate coefficients to j1 = 30, where j1 is the angular momentum quantum number of C6H-. State-to-state rate coefficients were obtained for temperatures ranging from 2 to 100 K. The rate coefficients for H2 collisions for Δj1 = -1 transitions are of the order of 10-10 cm3 s-1, a factor of 2 to 3 greater than those of He. Propensity rules are discussed. The collisional excitation rate coefficients produced here impact astrophysical modelling since they are required for obtaining accurate C6H- level populations and line emission for regions that contain anions.

  7. Ab initio based study of the ArO- photoelectron spectra: Selectivity of spin-orbit transitions

    NASA Astrophysics Data System (ADS)

    Buchachenko, A. A.; Jakowski, Jacek; Chałasiński, Grzegorz; Szczȩśniak, M. M.; Cybulski, S. M.

    2000-04-01

    A combined ab initio atoms-in-molecule approach was implemented to model the photoelectron spectra of the ArO- anion. The lowest adiabatic states of Σ and Π symmetry of ArO and ArO- were investigated using the fourth-order Møller-Plessett perturbation theory including bond functions. The total energies were dissected into electrostatic, exchange, induction, and dispersion components. The complex of Ar with atomic oxygen is only weakly bound, primarily by dispersion interaction. The Π state possesses a deeper minimum (Re=3.4Å,De=380μEh) than the Σ state (Re=3.8Å,De=220μEh). In contrast, the anion complex is fairly strongly bound, primarily by ion-induced dipole induction forces, and the Σ state possesses a deeper minimum at shorter interatomic distances (Re=3.02Å,De=3600μEh) than the Π state (Re=3.35Å,De=2400μEh). The Σ-Π splittings in both systems are mainly due to differences in the exchange repulsion terms. Atoms-in-molecule models were used to account for the spin-orbit interaction, and to generate adiabatic relativistic potentials and wave functions. Collisional properties, diffusion, and mobility coefficients of O and O- in Ar, and absolute total Ar+O scattering cross sections, were calculated and found to agree well with the available experimental data. The photoelectron spectra were simulated within vibronic model, and were found in excellent agreement with the experimental measurements. The bimodal electron kinetic energy distribution was shown to stem from the strong selectivity of spin-orbit transitions, which split into two dense groups, depending on the initial electronic state of the anion. The latter feature cannot be described without explicit consideration of electronic intensity factor.

  8. Policies and Practices. Shortening Children's Stays in Temporary Care, Part One. Family to Family: Tools for Rebuilding Foster Care.

    ERIC Educational Resources Information Center

    Annie E. Casey Foundation, Baltimore, MD.

    The Family to Family initiative has encouraged states to reconceptualize, redesign, and reconstruct their foster care systems. By 1996, the initiative was being implemented in five states and six counties in two additional states. Drawing on the experiences of Family to Family participants, a framework for child welfare leaders working to reduce…

  9. Children and Welfare Reform: What Policy Theories Are Being Implemented in States Where Most Poor Children Live?

    ERIC Educational Resources Information Center

    Johnson, Cathy Marie; Gais, Thomas Lewis; Lawrence, Catherine

    This paper revisits 1997-98 findings that indicated that during the first years of state implementation of Temporary Assistance for Needy Families (TANF), states were most likely to implement the environment theory, which claims that children benefit socially and psychologically from being part of a household in which caregivers have jobs, and…

  10. Influence of the protonation state on the binding mode of methyl orange with cucurbiturils

    NASA Astrophysics Data System (ADS)

    He, Suhang; Sun, Xuzhuo; Zhang, Haibo

    2016-03-01

    Binding modes of methyl orange (MO) with cucurbiturils (CBs) have been investigated by Single Crystal X-ray Diffraction and NMR Spectroscopy. Detailed study of intermolecular interactions was supported by the Hirshfeld surface analysis. Protonation state of the anionic part of methyl orange has greatly influenced the binding mode of the complex. Stabilized by hydrogen bonding at the portal, hydrophobic and dispersion interactions in the cavity, the protonated methyl orange was deeply inserted into the cavity. On the contrary, the anionic methyl orange has been pushed towards the outside of the cavity by the electrostatic repulsion between the azo group and the portal oxygen. A ;water bridge; was found in MO@CB8 linking both host and guest via hydrogen bonds.

  11. An automated exploration of the isomerization and dissociation pathways of (E)-1,2-dichloroethene cations and anions

    NASA Astrophysics Data System (ADS)

    Kishimoto, Naoki; Nishi, Yuito

    2017-04-01

    Isomerization and dissociation pathways after the photoionization or electron attachment of (E)-1,2-dichloroethene were calculated with an automated exploration method utilizing a scaled hypersphere search of the anharmonic downward distortion following algorithm at the UB3LYP/6-311G(2d,d,p) level of theory. The potential energies of transition states and dissociation channels were calculated by a composite method ((RO)CBS-QB3) and compared with the breakdown diagrams and electron attachment spectra observed in previous spectroscopic studies. The results of single point calculations with several DFT and post-SCF methods are compared using the root mean square deviations from the (RO)CBS-QB3 energies for six states of anionic dichloroethene.

  12. Absorption and resonance Raman study of the pyromellitic diahydride anion via density functional theory

    NASA Astrophysics Data System (ADS)

    Andruniow, T.; Pawlikowski, M.

    2000-05-01

    The electronic structure of the low-energy states of the pyromellitic diahydride (PMDA) anion is investigated in terms of the VWN (Vosco-Wilk-Nusair) the BP (Becke-Perdew) and the B3LYP density functional (DF) methods employed with 6-31G * basis sets. All the methods are shown to reproduce correctly the absorption and resonance Raman spectra in the region corresponding to the low-energy 1 2Au→1 2B3g transition. The discrepancies between the theory and experiment are attributed to a (weak) Dushinsky effect predominately due to a mixing of the ν3=1593 cm -1 and ν4=1342 cm -1 vibrations in the 1 2B3 g state of the PMDA radical.

  13. Conformation-selective resonant photoelectron imaging from dipole-bound states of cold 3-hydroxyphenoxide

    NASA Astrophysics Data System (ADS)

    Zhu, Guo-Zhu; Huang, Dao-Ling; Wang, Lai-Sheng

    2017-07-01

    We report a photoelectron imaging and photodetachment study of cryogenically cooled 3-hydroxyphenoxide (3HOP) anions, m-HO(C6H4)O-. In a previous preliminary study, two conformations of the cold 3HOP anions with different dipole bound states were observed [D. L. Huang et al., J. Phys. Chem. Lett. 6, 2153 (2015)]. Five near-threshold vibrational resonances were revealed in the photodetachment spectrum from the dipole-bound excited states of the two conformations. Here, we report a more extensive investigation of the two conformers with observation of thirty above-threshold vibrational resonances in a wide spectral range between 18 850 and 19 920 cm-1 (˜1000 cm-1 above the detachment thresholds). By tuning the detachment laser to the vibrational resonances in the photodetachment spectrum, high-resolution conformation-selective resonant photoelectron images are obtained. Using information of the autodetachment channels and theoretical vibrational frequencies, we are able to assign the resonant peaks in the photodetachment spectrum: seventeen are assigned to vibrational levels of anti-3HOP, eight to syn-3HOP, and five to overlapping vibrational levels of both conformers. From the photodetachment spectrum and the conformation-selective resonant photoelectron spectra, we have obtained fourteen fundamental vibrational frequencies for the neutral syn- and anti-m-HO(C6H4)Oṡ radicals. The possibility to produce conformation-selected neutral beams using resonant photodetachment via dipole-bound excited states of anions is discussed.

  14. A novel smart supramolecular organic gelator exhibiting dual-channel responsive sensing behaviours towards fluoride ion via gel-gel states.

    PubMed

    Mehdi, Hassan; Pang, Hongchang; Gong, Weitao; Dhinakaran, Manivannan Kalavathi; Wajahat, Ali; Kuang, Xiaojun; Ning, Guiling

    2016-07-07

    A novel smart supramolecular organic gelator G-16 containing anion and metal-coordination ability has been designed and synthesized. It shows excellent and robust gelation capability as a strong blue fluorescent supramolecular organic gel OG in DMF. Addition of Zn(2+) produced Zn(2+)-coordinated supramolecular metallogel OG-Zn. Organic gel OG and organometallic gel OG-Zn exhibited efficient and different sensing behaviors towards fluoride ion due to the variation in self-assembling nature. Supramolecular metallogel OG-Zn displayed specific selectivity for fluoride ion and formed OG-Zn-F with dramatic color change from blue to blue green in solution and gel to gel states. Furthermore after directly addition of fluoride into OG produced fluoride containing organic gel OG-F with drastically modulation in color from blue to greenish yellow fluorescence via strong aggregation-induced emission (AIE) property. A number of experiments were conducted such as FTIR, (1)H NMR, and UV/Vis spectroscopies, XRD, SEM and rheology. These results revealed that the driving forces involved in self-assembly of OG, OG-Zn, OG-Zn-F and OG-F were hydrogen bonding, metal coordination, π-π interactions, and van der Waal forces. In contrast to the most anion responsive gels, particularly fluoride ion responsive gels showed gel-sol state transition on stimulation by anions, the gel state of OG and OG-Zn did not show any gel-to-sol transition during the whole F(-) response process.

  15. Application of a macrocyclic compound, bambus[6]uril, in tailor-made liquid membranes for highly selective electromembrane extractions of inorganic anions.

    PubMed

    Šlampová, Andrea; Šindelář, Vladimír; Kubáň, Pavel

    2017-01-15

    A tailor-made liquid membrane consisting of a resistive organic solvent (nitrobenzene, NB) and a highly selective non-ionic macrocyclic compound (bambus[6]uril, BU6) was employed for electromembrane extraction (EME) of inorganic anions. BU6 facilitates strong host-guest interactions of its internal cavity with selected inorganic anions only and its presence in the liquid membrane ensured excellent selectivity of the EME process. EME transfers were directly related to association constants between BU6 and inorganic anions and nearly absolute selectivity was achieved for EMEs of iodide, bromide and perchlorate. Major inorganic anions (chloride, nitrate, sulphate and carbonate), which exhibit low interactions with BU6 cavity, were efficiently eliminated from the EME transfer. No interferences were observed for EMEs of target analytes from samples containing up to 100.000-fold higher concentrations of the major anions. Addition of species-specific macrocyclic modifiers to free and supported liquid membranes might thus open new directions in fine-tuning of EME selectivity. At optimized EME conditions (polypropylene hollow fiber impregnated with NB + 3% (w/w) BU6, extraction voltage 25 V, extraction time 15 min, deionized water as acceptor solution) perchlorate was selectively extracted from tap water at concentrations below the guideline value recommended by United States Environmental Protection Agency. Excellent selectivity of the tailor-made liquid membrane was further demonstrated by EME of bromide from sea water. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Perspective: Electrospray photoelectron spectroscopy: From multiply-charged anions to ultracold anions

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wang, Lai-Sheng, E-mail: Lai-Sheng-Wang@brown.edu

    2015-07-28

    Electrospray ionization (ESI) has become an essential tool in chemical physics and physical chemistry for the production of novel molecular ions from solution samples for a variety of spectroscopic experiments. ESI was used to produce free multiply-charged anions (MCAs) for photoelectron spectroscopy (PES) in the late 1990 s, allowing many interesting properties of this class of exotic species to be investigated. Free MCAs are characterized by strong intramolecular Coulomb repulsions, which create a repulsive Coulomb barrier (RCB) for electron emission. The RCB endows many fascinating properties to MCAs, giving rise to meta-stable anions with negative electron binding energies. Recent developmentmore » in the PES of MCAs includes photoelectron imaging to examine the influence of the RCB on the electron emission dynamics, pump-probe experiments to examine electron tunneling through the RCB, and isomer-specific experiments by coupling PES with ion mobility for biological MCAs. The development of a cryogenically cooled Paul trap has led to much better resolved PE spectra for MCAs by creating vibrationally cold anions from the room temperature ESI source. Recent advances in coupling the cryogenic Paul trap with PE imaging have allowed high-resolution PE spectra to be obtained for singly charged anions produced by ESI. In particular, the observation of dipole-bound excited states has made it possible to conduct vibrational autodetachment spectroscopy and resonant PES, which yield much richer vibrational spectroscopic information for dipolar free radicals than traditional PES.« less

  17. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mani, Tomoyasu; Grills, David C.

    Delocalization of charges is one of the factors controlling charge transport in conjugated molecules. It is considered to play an important role in the performance of a wide range of molecular technologies, including organic solar cells and organic electronics. Dimerization reactions are well-suited as a model to investigate intermolecular spatial delocalization of charges. And while dimerization reactions of radical cations are well investigated, studies on radical anions are still scarce. Upon dimerization of radical anions with neutral counterparts, an electron is considered to delocalize over the two molecules. By using time-resolved infrared (TRIR) detection coupled with pulse radiolysis, we showmore » that radical anions of 4-n-hexyl-4'-cyanobiphenyl (6CB) undergo such dimerization reactions, with an electron equally delocalized over the two molecules. We have recently demonstrated that nitrile ν(C≡N) vibrations respond to the degree of electron localization of nitrile-substituted anions: we can quantify the changes in the electronic charges from the neutral to the anion states in the nitriles by monitoring the ν(C≡N) IR shifts. In the first part of this article, we show that the sensitivity of the ν(C≡N) IR shifts does not depend on solvent polarity. In the second part, we describe how probing the shifts of the nitrile IR vibrational band unambiguously confirms the formation of dimer radical anions, with K dim = 3 × 10 4 M –1. IR findings are corroborated by electronic absorption spectroscopy and electronic structure calculations. We find that the presence of a hexyl chain and the formation of π–π interactions are both crucial for dimerization of radical anions of 6CB with neutral 6CB. Our study provides clear evidence of spatial delocalization of electrons over two molecular fragments.« less

  18. Implementation of a DOD ELAP Conforming Quality System at a FUSRAP Site Field Temporary Radiological Screening Laboratory - 13500

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Winters, M.S.; McElheny, G.; Houston, L.M.

    2013-07-01

    A case study is presented on specific program elements that supported the transition of a temporary field radiological screening lab to an accredited operation capable of meeting client quality objectives for definitive results data. The temporary field lab is located at the Formerly Utilized Sites Remedial Action Program Linde Site in Tonawanda, NY. The site is undergoing remediation under the direction of the United States Army Corps of Engineers - Buffalo District, with Cabrera Services Inc. as the remediation contractor and operator of the on-site lab. Analysis methods employed in the on-site lab include gross counting of alpha and betamore » particle activity on swipes and air filters and gamma spectroscopy of soils and other solid samples. A discussion of key program elements and lessons learned may help other organizations considering pursuit of accreditation for on-site screening laboratories. (authors)« less

  19. Anion binding in biological systems

    NASA Astrophysics Data System (ADS)

    Feiters, Martin C.; Meyer-Klaucke, Wolfram; Kostenko, Alexander V.; Soldatov, Alexander V.; Leblanc, Catherine; Michel, Gurvan; Potin, Philippe; Küpper, Frithjof C.; Hollenstein, Kaspar; Locher, Kaspar P.; Bevers, Loes E.; Hagedoorn, Peter-Leon; Hagen, Wilfred R.

    2009-11-01

    We compare aspects of biological X-ray absorption spectroscopy (XAS) studies of cations and anions, and report on some examples of anion binding in biological systems. Brown algae such as Laminaria digitata (oarweed) are effective accumulators of I from seawater, with tissue concentrations exceeding 50 mM, and the vanadate-containing enzyme haloperoxidase is implicated in halide accumulation. We have studied the chemical state of iodine and its biological role in Laminaria at the I K edge, and bromoperoxidase from Ascophyllum nodosum (knotted wrack) at the Br K edge. Mo is essential for many forms of life; W only for certain archaea, such as Archaeoglobus fulgidus and the hyperthermophilic archaeon Pyrococcus furiosus, and some bacteria. The metals are bound and transported as their oxo-anions, molybdate and tungstate, which are similar in size. The transport protein WtpA from P. furiosus binds tungstate more strongly than molybdate, and is related in sequence to Archaeoglobus fulgidus ModA, of which a crystal structure is known. We have measured A. fulgidus ModA with tungstate at the W L3 (2p3/2) edge, and compared the results with the refined crystal structure. XAS studies of anion binding are feasible even if only weak interactions are present, are biologically relevant, and give new insights in the spectroscopy.

  20. A theoretical study of the decomposition of gold (I) complexes

    NASA Astrophysics Data System (ADS)

    Tossell, J. A.

    1998-04-01

    Structures, energetics and excitation energies are calculated for the gold (I) complexes CH 3Au, (CH 3) 2Au -, CH 3AuOH 2, CH 3AuPH 3 and PH 3AuCl at the Hartree-Fock and MP2 levels of theory, and for CH 3AuP(CH 3) 3, CH 3AuP(OH) 3 and Au 3Cl 3 at the HF level. The lowest-energy neutral triplet state of each 2-coordinate compound dissociates into either two or three radical species (always including the CH 3 radical), with the exception of (CH 3) 2Au - which shows only slight Au-C bond elongation. In contrast, the doublet anion states dissociate neutral ligands, like PH 3, but do not dissociate CH 3. These results indicate that gold (I) chemical vapor deposition processes must involve excited states of the neutrals rather than their anions.

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