662 research outputs found

    Leadership style and its relation to employee attitudes and behaviour.

    Get PDF
    The purpose of this study was to determine the relationships between leadership style and organisational commitment, job satisfaction, job involvement and organisational citizenship behaviour and whether these relationships were stronger for transformational than for transactional leaders. A sample of 52 leaders and 276 raters from a world class engineering company participated. The results of a canonical correlation analysis using the rater data indicated that the most prominent relationship was that between transactional leadership and affective commitment. Furthermore, transformational and transactional leadership did not correlate significantly with the constructs of job involvement and job satisfaction

    Preparation and characterization of Bi26–2xMn2xMo10O69-d and Bi26.4Mn0.6Mo10–2yMe2yO69-d(Me = V, Fe) solid solutions

    Get PDF
    Received: 06.06.2017; accepted: 23.06.2017; published: 14.07.2017.Single phase samples of bismuth molybdate, Bi26Mo10O69, doped with Mn on the bismuth sublattice and V, Fe on the molybdenum sublattice were found to crystallize in the triclinic Bi26Mo10O69 structure at low doping levels and in the monoclinic Bi26Mo10O69 structure - at higher dopant concentration. The assumption that all Mn ions have an oxidation state of +2 was confirmed by means of magnetic measurement results analysis using Curie-Weiss law. Conductivity was investigated using impedance spectroscopy. The conductivity of Bi26.4Mn0.6Mo9.6Fe0.4O69-d was 1.2*10-2 S*cm-1 at 973 K and 2.2*10-4 S*cm-1 at 623 K, and the conductivity of Bi26.4Mn0.6Mo9.2V0.8O69-d was 2.2*10-3 S*cm-1 at 973 K and 2.2*10-5 S*cm-1 at 623 K

    Multi-Wavelength Variability of the Synchrotron Self-Compton Model for Blazar Emission

    Get PDF
    Motivated by recent reports of strongly correlated radio and X-ray variability in 3C279 (Grandi, etal 1995), we have computed the relative amplitudes of variations in the synchrotron flux at ν\nu and the self-Compton X-ray flux at 1 keV (R(ν)R(\nu)) for a homogeneous sphere of relativistic electrons orbiting in a tangled magnetic field. Relative to synchrotron self-Compton scattering without induced Compton scattering, stimulated scattering reduces the amplitude of R(ν)R(\nu) by as much as an order of magnitude when \tau_T \gtwid 1. When τT\tau_T varies in a fixed magnetic field, RτR_{\tau} increases monotonically from 0.01 at νo\nu_o, the self-absorption turnover frequency, to 0.50.5 at 100νo100 \nu_o. The relative amplitudes of the correlated fluctuations in the radio-mm and X-ray fluxes from 3C279 are consistent with the synchrotron self-Compton model if τT\tau_T varies in a fixed magnetic field and induced Compton scattering is the dominant source of radio opacity. The variation amplitudes are are too small to be produced by the passage of a shock through the synchrotron emission region unless the magnetic field is perpendicular to the shock front.Comment: 21 pages, 4 fig

    Evidence of s-wave pairing symmetry in layered superconductor Li0.68_{0.68}NbO2_2 from the specific heat measurement

    Full text link
    A high quality superconducting Li0.68_{0.68}NbO2_2 polycrystalline sample was synthesized by deintercalation of Li ions from Li0.93_{0.93}NbO2_2. The field dependent resistivity and specific heat were measured down to 0.5 K. The upper critical field Hc2(T)H_{c2} (T) is deduced from the resistivity data and Hc2(0)H_{c2}(0) is estimated to be 2.98\sim 2.98 T. A notable specific heat jump is observed at the superconducting transition temperature Tc5.0T_c \sim 5.0 K at zero field. Below TcT_c, the electronic specific heat shows a thermal activated behavior and agrees well with the theoretical result of the BCS s-wave superconductors. It indicates that the superconducting pairing in Li0.68_{0.68}NbO2_2 has s-wave symmetry.Comment: 4 pages, 5 figure

    Magnetism and structure of LixCoO2 and comparison to NaxCoO2

    Full text link
    The magnetic properties and structure of LixCoO2 for x between 0.5 and 1.0 are reported. Co4+ is found to be high-spin in LixCoO2 for x between 0.94 and 1.0 and low-spin for x between 0.50 and 0.78. Weak antiferromagnetic coupling is observed, increasing in strength as more Co4+ is introduced. At an x value of about 0.65, the temperature-independent contribution to the magnetic susceptibility and the electronic contribution to the specific heat are largest. Neutron diffraction analysis reveals that the lithium oxide layer expands perpendicular to the basal plane and the Li ions displace from their ideal octahedral sites with decreasing x. A comparison of the structures of the NaxCoO2 and LixCoO2 systems reveals that the CoO2 layer changes substantially with alkali content in the former but is relatively rigid in the latter. Further, the CoO6 octahedra in LixCoO2 are less distorted than those in NaxCoO2. We postulate that these structural differences strongly influence the physical properties in the two systems

    SYNTHESIS AND STUDY OF SiO2-LiFe5O8 COMPOSITE MATERIAL

    Full text link
    The lithium ferrite (LiFe50 8) is a very interesting ferromagnetic material due to its square hysteresis loop and high Curie temperature. It has attracted the attention of scientists and engineers for a long time with regard to its application as a low-cost substitute of garnet ferrites in various devices. In this work we present the first studies of the 90SiO2-10LiFe5O8 (mol.%) glass prepared by the sol-gel method

    Spectroscopy of the near-nuclear regions of Cygnus A: estimating the mass of the supermassive black hole

    Get PDF
    We use a combination of high spatial resolution optical and near-IR spectroscopic data to make a detailed study of the kinematics of the NLR gas in the near-nuclear regions of the powerful, FRII radio galaxy Cygnus A (z=0.0560), with the overall goal of placing limits on the mass of any supermassive black hole in the core. Our K-band infrared observations (0.75 arcsec seeing) -- taken with NIRSPEC on the Keck II telescope -- show a smooth rotation pattern across the nucleus in the Paschen alpha and H_2 emission lines along a slit position (PA180) close to perpendicular to the radio axis, however, there is no evidence for such rotation along the radio axis (PA105). Higher spatial resolution observations of the [OIII]5007 emission line -- taken with STIS on the Hubble Space Telescope (HST) -- confirm the general rotation pattern of the gas in the direction perpendicular to the radio axis, and provide evidence for steep velocity gradients within a radius of 0.1 arcsec of the core. The circular velocities measured from both the Keck and HST data lead to an estimate of the mass of the supermassive black hole of 2.5+/-0.7x10^9 solar masses. For the host galaxy properties of Cygnus A, this mass is consistent with the global correlations between black hole mass and host galaxy properties deduced for non-active galaxies. Therefore, despite the extreme power of its radio source and the quasar-like luminosity of its AGN, the black hole in Cygnus A is not unusually massive considering theluminosity of its host galaxy. Indeed, the estimated mass of the black hole in Cygnus A is similar to that inferred for the supermassive black hole in the FRI radio galaxy M87, despite the fact that the AGN and radio jets of Cygnus A are 2 -- 3 orders of magnitude more powerful.Comment: 17 pages, 12 figure
    corecore