7,181 research outputs found
Structural Isomorphism in Australian Nonprofit Organisations
This paper assesses the extent of structural similarity or isomorphism among non-profit organizations in Australia. Based on neo-institutional theory, the paper explains such isomorphism in terms of these organizations’ subordination and dependency, the uncertainties they face, and the networks of experts of which they are a part. The analysis uses the non-profit component of a 2001-2002 random sample of Australian employment organizations. It finds surprisingly little isomorphism in this subsample and few differences in isomorphism according to the level of the factors thought to produce similarity. The discussion of the findings focuses on the suitability of the non-profit sector as the appropriate organizational field within which isomorphism involving these organizations is likely to be produced. Industries, which include all organizations that produce the same product or service, be they non-profit, for-profit, or government, may be more appropriate interactional fields for the development of isomorphis
The Penrose photoproduction scenario for NGC 4151: A black hole gamma-ray emission mechanism for active galactic nuclei and Seyfert galaxies
A consistent theoretical interpretation is given for the suggestion that a steepening of the spectrum between X-ray and gamma ray energies may be a general, gamma-ray characteristic of Seyfert galaxies, if the diffuse gamma ray spectrum is considered to be a superposition of unresolved contributions, from one or more classes of extragalactic objects. In the case of NGC 4151, the dominant process is shown to be Penrose Compton scattering in the ergosphere of a Kerr black hole, assumed to exist in the Seyfert's active galactic nucleus
Spectral evolution of active galactic nuclei: A unified description of the X-ray and gamma
A model for spectral evolution is presented whereby active galactic nuclei (AGN) of the type observed individually emerge from an earlier stage at z approx = 4 in which they are the thermal X-ray sources responsible for most of the cosmic X-ray background (CXB). The conjecture is pursued that these precursor objects are initially supermassive Schwarzschild black holes with accretion disks radiating near the Eddington luminosity limit. It is noted that after approx. 10 to the 8th power years these central black holes are spun-up to a canonical Kerr equilibrium state (A/M = 0.998; Thorne 1974) and shown how they then can lead to spectral evolution involving non-thermal emission extending to gamma rays, at the expense of reduced thermal disk radiation. That major portion of the CXB remaining after the contribution of usual AGN are considered, while a superposition of AGN sources at z 1 can account for the gamma ray background. Extensive X-ray measurements carried out with the HEAO 1 and 2 missions as well as gamma ray and optical data are shown to compare favorably with principal features of this model
The Convergence of Health Care Financing Structures: Empirical Evidence from OECD-Countries
In this paper we concentrate on the question whether the financing structure of the health care systems converges. In a world of increasing economic integration convergence in health care financing (HCF) and, hence, decreasing differences in HCF across countries enhance individuals’ (labour) mobility and support harmonization processes. As an indicator for convergence we take the public financing ratio in % of total HCF and in % of GDP. The major finding is that HCF in the OECD countries converged in the time period 1970 – 2005. This conlusion also holds when looking at smaller sub groups of countries and shorter time periods. However, we find evidence that countries do not move towards a common mean and that the rate of convergence is decreasing over time.Convergence, health care system, health care financing
Spectral-luminosity evolution of active galactic nuclei and the cosmic X- and gamma ray background
Coherent electromagnetic dynamo acceleration processes, which act on charge particles within the context of black hole accretion disk scenarios, are generally regarded as the underlying central power source for active galactic nuclei (AGN). If the precursor active galaxies (PAG) for such AGN are formed at high redshift and contain initial seed black holes with mass approximately equal to 10(exp 4) solar masses, then the Eddington limited X-ray radiation emitted during their lifetime will undergo the phenomenon of 'spectral-luminosity evolution'. When accretion disks are first formed at the onset of galaxy formation the accretion rate occurs at very high values of luminosity/size compactness parameter L/R greater than 10(exp 30) erg/cm-sec. In the absence of extended structure, such high values of L/R generate dynamic constraints which suppress coherent, black hole/accretion disk dynamo particle acceleration processes. This inhibits nonthermal radiation processes and causes the spectrum of X-radiation emitted by PAG to be predominantly thermal. A superposition of PAG sources at z is greater than or equal to 6 can account for the residual cosmic X-ray background (CXB) obtained from the total CXB after subtraction of foreground AGN sources associated with present epoch Seyfert galaxies. The manner in which the PAG undergo spectral-luminosity evolution into Seyfert galaxies is investigated
Optical characteristics of young quasars as sources of the cosmic X-ray background
The sources which dominate the thermal cosmic X-ray background cannot have X-ray spectra similar to the power laws measured for bright active galactic nuclei. The optical consequences of this disparity are pursued by considering a standard model for the photoexcitation and heating of the line emitting gas surrounding a central source (e.g., such as a quasar). The optical line emission to be associated with compact young quasar sources having the same X-ray spectrum as the X-ray background is found to be substantially different from that characteristic of typical quasars. Implications on quasar source counts and the identification of such new objects are discussed
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