26,304 research outputs found

    Co-operative Development and Corporate Governance Structures in German Co-operatives: Problems and Perspectives

    Get PDF
    In Germany exist a large number of co-operatives that are engaged in a broad variety of business activities. Their organisational structure is determined by co-operative law and to a lesser degree by statutes or by-laws. As has been shown for German rural co-operatives by applying property rights theory the corporate governance structure as determined by law is formally still in existence, while it actually has been shifted in favour of the executive board. This has created an imbalance where on the one hand no longer any corporate governance is actually taking place while on the other hand members' interests may easily be neglected, because it is the executive board that determines the members' interests and also whether they have benefited from the cooperatives activities. In theory, suitable instruments to improve the corporate governance structure within such co-operative are the promotion plan and the promotion report as developed by Boettcher. However, for transaction cost reasons and due to the current attenuation of property rights, it is unlikely that these instruments will be implemented without outside pressure, e. g. through a change in cooperative law. A superior alternative to promotion plan and promotion report may be a combination of promotion task controlling and member oriented quality management. While such instruments would indeed improve members' ability to execute co-operative governance, managers' willingness to submit themselves to stronger governance may well be assumed to be very low. Taking into account the current distribution of property rights in big German co-operatives, managers will accept stronger governance structures only if some other incentives exist. An ongoing research project indicates that such incentives might exist in the realm of improved business opportunities due to better information about members' aims and needs. --

    The First Eigenvalue of the Dirac Operator on Quaternionic Kaehler Manifolds

    Full text link
    In a previous paper we proved a lower bound for the spectrum of the Dirac operator on quaternionic Kaehler manifolds. In the present article we show that the only manifolds in the limit case, i.e. the only manifolds where the lower bound is attained as an eigenvalue, are the quaternionic projective spaces. We use the equivalent formulation in terms of the quaternionic Killing equation and show that a nontrivial solution defines a parallel spinor on the associated hyperkaehler manifold.Comment: 19 pages, LaTeX2e, fullpage styl

    Tungsten-rhenium alloy thermocouples effective for high-temperature measurement

    Get PDF
    Tungsten-rhenium alloy thermocouples, specifically, insulated, sheathed W/W plus 26Re and W plus 5 Re/W plus 26 Re thermocouples, are effective for temperature measurement in excess of 2920 degrees C. These thermocouples have a high thermoelectric output and excellent relationship to temperatures up to 2760 degrees C

    High-resolution single-pulse studies of the Vela Pulsar

    Get PDF
    We present high-resolution multi-frequency single-pulse observations of the Vela pulsar, PSR B0833-45, aimed at studying micro-structure, phase-resolved intensity fluctuations and energy distributions at 1.41 and 2.30 GHz. We show that the micro-pulse width in pulsars has a period dependence. Like individual pulses, Vela's micro-pulses are highly elliptically polarized. There is a strong correlation between Stokes parameters V and I in the micro-structure. We show that the V/I distribution is Gaussian with a narrow width and that this width appears to be constant as a function of pulse phase. The phase-resolved intensity distributions of I are best fitted with log-normal statistics. Extra emission components, i.e.``bump'' and ``giant micro-pulses'', discovered by Johnston et al.(2001) are also present at 2.3 GHz. The bump component seems to be an extra component superposed on the main pulse profile but does not appear periodically. The giant micro-pulses are time-resolved and have significant jitter in their arrival times. Their flux density distribution is best fitted by a power-law, indicating a link between these features and ``classical'' giant pulses as observed for the Crab pulsar, (PSR B0531+21), PSR B1937+21 and PSR B1821-24. We find that Vela contains a mixture of emission properties representing both ``classical'' properties of radio pulsars (e.g. micro-structure, high degree of polarization, S-like position angle swing, orthogonal modes) and features which are most likely related to high-energy emission (e.g. extra profile components, giant micro-pulses). It hence represents an ideal test case to study the relationship between radio and high-energy emission in significant detail.Comment: accepted for publication in MNRAS (11 pages, 10 figures

    The 2-10 keV emission properties of PSR B1937+21

    Get PDF
    We present the results of a BeppoSAX observation of the fastest pulsar known: PSR B1937+21. The ~ 200 ks observation (78.5 (34) ks MECS (LECS) exposure times) allowed us to investigate with high statistical significance both the spectral properties and the pulse profile shape. The absorbed power law spectral model gave a photon index of ~ 1.7 and N_H ~ 2.3 x 10^22 cm^-2. These values explain both a) the ROSAT non-detection and b) the deviant estimate of a photon index of ~ 0.8 obtained by ASCA. The pulse profile appears, for the first time, clearly double peaked with the main component much stronger than the other. The statistical significance is 10 sigma (main peak) and 5 sigma (secondary peak). The 1.6-10 keV pulsed fraction is consistent with 100%; only in the 1.6-4 keV band there is a ~ 2 sigma indication for a DC component. The secondary peak is detected significantly only for energies above 3 / 4 keV. The unabsorbed (2-10 keV) flux is F_2-10 = 3.7 x 10^-13 erg cm^-2 s^-1, implying a luminosity of L_X = 4.6 x 10^31 Theta (d/3.6 kpc)^2 erg s^-1 and an X-ray efficiency of eta = 4 x 10^-5 Theta, where Theta is the solid angle spanned by the emission beam. These results are in agreement with those obtained by ASCA.Comment: 4 pages, 4 figures, 2 tables. To appear in the Proceedings of the 270. WE-Heraeus Seminar on Neutron Stars, Pulsars and Supernova Remnants, Jan. 21-25, 2002, Physikzentrum Bad Honnef, eds W. Becker, H. Lesch & J. Truemper. Proceedings are available as MPE-Report 27

    Dispersion of tracers in two-dimensional bounded turbulence

    Get PDF
    • 

    corecore