197 resultados para Economics, Econometrics and Finance (miscellaneous)
Resumo:
This article investigates corporate governance reform in South Africa in the context of the country’s international links with Anglo-American corporate governance and domestic pursuit of socioeconomic development. Two key questions are evaluated. (a) How has divergence within the Anglo-American model influenced corporate governance reform in South Africa? (b) Can South Africa’s historical closeness to the Anglo-American model be combined with increasing attention to stakeholder issues to produce a hybrid “African model” of corporate governance? Evaluating these questions, the following issues are explored in turn: the contrast between shareholder and stakeholder models, divergence between U.S. and U.K. approaches to corporate governance as exemplified by Sarbanes-Oxley, locating a South African approach in context of the Anglo-American model, the King reports and an emerging “African” model of corporate governance, and the role of international and domestic factors in shaping South Africa’s ongoing reform process.
Resumo:
Temple Period Malta in the 3rd millennium BC saw the production of a range of figurative and decorative art and architecture that implies a richly populated spiritual and cognitive world associated with ritual practice in life and death. The paper explores the potential to categorize the figurative art into distinct groups, and how these various images might represent aspects of the cosmology and social concerns of a prehistoric island society.
Resumo:
Cilliní—or children’s burial grounds—were the designated resting places for unbaptized infants and other members of Irish society who were considered unsuitable by the Roman Catholic Church for burial in consecrated ground. The sites appear to have proliferated from the seventeenth century onwards in the wake of the Counter-Reformation. While a number of previous studies have attempted to relate their apparently marginal characteristics to the liminality of Limbo, evidence drawn from the archaeological record and oral history accounts suggests that it was only the Roman Catholic Church that considered cilliní, and those interred within, to be marginal. In contrast, the evidence suggests that the families of the dead regarded the cemeteries as important places of burial and treated them in a similar manner to consecrated burial grounds.
Resumo:
A computer code has been developed to simulate and study the evolution of ion charge states inside the trap region of an electron beam ion trap. In addition to atomic physics phenomena previously included in similar codes such as electron impact ionization, radiative recombination, and charge exchange, several aspects of the relevant physics such as dielectronic recombination, ionization heating, and ion cloud expansion have been included for the first time in the model. The code was developed using object oriented concepts with database support, making it readable, accurate, and well organized. The simulation results show a good agreement with various experiments, and give useful information for selection of operating conditions and experiment design.
Resumo:
When the dominant mechanism for ion acceleration is the laser radiation pressure, the conversion efficiency of the laser energy into the energy of relativistic ions may be very high. Stability analysis of a thin plasma layer accelerated by the radiation pressure shows that Raleigh-Taylor instability may enhance plasma inhomogeneity. In the linear stage of instability, the plasma layer decays into separate bunches, which are accelerated by the radiation pressure similarly to clusters accelerated under the action of an electromagnetic wave. The energy and luminosity of an ion beam accelerated in the radiation-pressure-dominated regime are calculated.
Resumo:
Energetic ion beams are produced during the interaction of ultrahigh-intensity, short laser pulses with plasmas. These laser-produced ion beams have important applications ranging from the fast ignition of thermonuclear targets to proton imaging, deep proton lithography, medical physics, and injectors for conventional accelerators. Although the basic physical mechanisms of ion beam generation in the plasma produced by the laser pulse interaction with the target are common to all these applications, each application requires a specific optimization of the ion beam properties, that is, an appropriate choice of the target design and of the laser pulse intensity, shape, and duration.
Resumo:
High contrast proton moire fringes have been obtained in a laser-produced proton beam. Moire u fringes with modulation of 20%-30% were observed in protons with energies in the range of 4 - 7 MeV. Monte Carlo simulations with simple test fields showed that shifts in the moire u fringes can be used to give quantitative information on the strength of transient electromagnetic fields inside plasmas and materials that are opaque to conventional probing methods. (C) 2003 American Institute of Physics.
Resumo:
Silver nanorods have been grown by electrodeposition into thin film porous alumina templates (AAO). Optical transmission measurements using p-polarized incident white light shows clear plasmon resonance extinction peaks. We successfully model the dependence on angle in incidence of extinction peak height and position using a multiple-multipoles (MMP) approach with the different spectral features being clearly associated with the effective electric field distribution and coupling between individual nanorods.