7,812 research outputs found

    Die struktuur en dinamika van die Suid-Afrikaanse politieke omgewing: 'n post-apartheidsperspektief

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    The most important concepts during the first term of government in the ''New South Africa" were reconstruction and development, transformation and deracialisation. Landmarks on the road to transformation were: the 1994 election, the final constitution, the Reconstruction and Development Programme and GEAR. These are placed in a first and second term perspective. The way in which transformation led South Africa on a road to democracy is analysed and possible adaptations of existing state and political practices which could strengthen the ideal o fgood governance are investigated

    Election of 2 June 1999: contextual overview and statistical profile

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    On Wednesday, 2 June J999, South Africans cast their votes in an election which comprised two ballot papers: the first, for the National Assembly, and, the second, for their provincial legislature

    Imaging Pulsed Laser Deposition oxide growth by in-situ Atomic Force Microscopy

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    To visualize the topography of thin oxide films during growth, thereby enabling to study its growth behavior quasi real-time, we have designed and integrated an atomic force microscope (AFM) in a pulsed laser deposition (PLD) vacuum setup. The AFM scanner and PLD target are integrated in a single support frame, combined with a fast sample transfer method, such that in-situ microscopy can be utilized after subsequent deposition pulses. The in-situ microscope can be operated from room temperature (RT) up to 700∘^\circC and at (process) pressures ranging from the vacuum base pressure of 10−6^{-6} mbar up to 1 mbar, typical PLD conditions for the growth of oxide films. The performance of this instrument is demonstrated by resolving unit cell height surface steps and surface topography under typical oxide PLD growth conditions.Comment: 8 pages, 8 figure

    The amalgamation of mechanical, electrical and software technology to remove manual tasks performed in a vehicle rental business

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    Published ArticleMost operational businesses today are restricted to normal business hours, as it is not cost effective for a business to operate on a 24-hour basis. Not only will operational costs increase substantially, in addition to these increases, the company will be faced with numerous challenges that range from security to staffing. Over the years, technology has proven to be an asset in which businesses could invest and enjoy the rewards of their investment in the form of an increase in employee efficiency, ease of new procedural implementations and the enforcement of governance. This process of continuous refinement has resulted in business systems developing to a point where the input required from an employee has been limited to the bare minimum. With the flexibility, dependability and affordability of technology today any operational business can reduce the need for human input into their systems. This article discusses the techniques employed by the researcher to stratify the hypothesis that the amalgamating of mechanical, electrical and software technologies will remove manual tasks performed by staff in a vehicle rental business

    Local Environment of Ferromagnetically Ordered Mn in Epitaxial InMnAs

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    The magnetic properties of the ferromagnetic semiconductor In0.98Mn0.02As were characterized by x-ray absorption spectroscopy and x-ray magnetic circular dichroism. The Mn exhibits an atomic-like L2,3 absorption spectrum that indicates that the 3d states are highly localized. In addition, a large dichroism at the Mn L2,3 edge was observed from 5-300 K at an applied field of 2T. A calculated spectrum assuming atomic Mn2+ yields the best agreement with the experimental InMnAs spectrum. A comparison of the dichroism spectra of MnAs and InMnAs show clear differences suggesting that the ferromagnetism observed in InMnAs is not due to hexagonal MnAs clusters. The temperature dependence of the dichroism indicates the presence of two ferromagnetic species, one with a transition temperature of 30 K and another with a transition temperature in excess of 300 K. The dichroism spectra are consistent with the assignment of the low temperature species to random substitutional Mn and the high temperature species to Mn near-neighbor pairs.Comment: 10 pages, 4 figures, accepted by Applied Physics Letter

    Group classification of the Sachs equations for a radiating axisymmetric, non-rotating, vacuum space-time

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    We carry out a Lie group analysis of the Sachs equations for a time-dependent axisymmetric non-rotating space-time in which the Ricci tensor vanishes. These equations, which are the first two members of the set of Newman-Penrose equations, define the characteristic initial-value problem for the space-time. We find a particular form for the initial data such that these equations admit a Lie symmetry, and so defines a geometrically special class of such spacetimes. These should additionally be of particular physical interest because of this special geometric feature.Comment: 18 Pages. Submitted to Classical and Quantum Gravit

    Is there a reentrant glass in binary mixtures?

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    By employing computer simulations for a model binary mixture, we show that a reentrant glass transition upon adding a second component only occurs if the ratio α\alpha of the short-time mobilities between the glass-forming component and the additive is sufficiently small. For α≈1\alpha \approx 1, there is no reentrant glass, even if the size asymmetry between the two components is large, in accordance with two-component mode coupling theory. For α≪1\alpha \ll 1, on the other hand, the reentrant glass is observed and reproduced only by an effective one-component mode coupling theory.Comment: 4 pages, 3 figure

    Compatibility of phenomenological dipole cross sections with the Balitsky-Kovchegov equation

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    Phenomenological models of the dipole cross section that enters in the description of for instance deep inelastic scattering at very high energies have had considerable success in describing the available small-x data in both the saturation region and the so-called extended geometric scaling (EGS) region. We investigate to what extent such models are compatible with the numerical solutions of the Balitsky-Kovchegov (BK) equation which is expected to describe the nonlinear evolution in x of the dipole cross section in these momentum regions. We find that in the EGS region the BK equation yields results that are qualitatively different from those of phenomenological studies. In particular, geometric scaling around the saturation scale is only obtained at asymptotic rapidities. We find that in this limit, the anomalous dimension \gamma(r,x) of phenomenological models approaches a limiting function that is universal for a large range of initial conditions. At the saturation scale, this function equals approximately 0.44, in contrast to the value 0.628 commonly used in the models. We further investigate the dependence of these results on the starting distribution, the small-r limit of the anomalous dimension for fixed rapidities and the x-dependence of the saturation scale.Comment: 14 pages, 8 figures. Extensive revisions, several new results, plots, references and conclusions added; to appear in Phys.Rev.

    Semantics and Proof Theory of the Epsilon Calculus

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    The epsilon operator is a term-forming operator which replaces quantifiers in ordinary predicate logic. The application of this undervalued formalism has been hampered by the absence of well-behaved proof systems on the one hand, and accessible presentations of its theory on the other. One significant early result for the original axiomatic proof system for the epsilon-calculus is the first epsilon theorem, for which a proof is sketched. The system itself is discussed, also relative to possible semantic interpretations. The problems facing the development of proof-theoretically well-behaved systems are outlined.Comment: arXiv admin note: substantial text overlap with arXiv:1411.362
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