26,304 research outputs found
Co-operative Development and Corporate Governance Structures in German Co-operatives: Problems and Perspectives
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
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
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
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
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
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