152 research outputs found

    “Living Under Different Skies”: Misrepresenting Egyptian Education during the British Occupation in the North American Press

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    During the British occupation from 1882 to 1922, Egypt saw the rise of colonial educational reforms, American missionary projects, and foreign-subsidized schools. Consequently, newspapers in North America reported extensively on these colonial educational excursions. In the view of correspondents, the so-called “enlightenment” of Egyptians was dependent on their adoption of Western moral ideals and instructional models. The main criticisms levelled at Egyptian education centred on what was viewed as the “incompetence” of native instructors and schools, namely Muslim ones, as well as the need for the modern education of young women. Moreover, Christian or Western schooling was posited as the way to “civilize” these indigenous populations. Overall, these writings not only helped simultaneously construct both the “abroad” and the oppositional, superior identity of the West to readers, but also legitimated the British occupation as a whole. Therefore, journalism in North America was upholding and reinforcing a colonially-mediated representation of the realities in Egypt. In response to this misrepresentation, Egyptian writers and activists took to Western publications to dispel such denigrating narratives and appealing to readers to consider the failures of their British colonizers. This study of collected articles on Egyptian education in North American newspapers at the time reveals and deconstructs Western observers’ misrepresentations of schools and teaching and learning activities in Egypt

    ON THE CUSPIDALITY OF MAASS-GRITSENKO AND MIXED LEVEL LIFTS

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    The production and evaluation of squeeze cast A1-alloy matrix-short ceramic fibre composites

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    Research work on metal matrix-fibre composites has concentrated in the past on aligned fibre composites. The poor transverse strength of these composites is seen as a major hindrance to their practical use in the majority of engineering applications because stresses exist in more than one direction. Materials with isotropic properties are preferred and consequently reinforcement of composites in three dimensions will be necessary. With this objective, an investigation was conducted to assess the method of fabrication and properties of A1-a110y reinforced with short fibres (SiC and A1 203) randomly oriented in three dimensions. Two composite systems were examined: Al-4.S Cu alloy reinforced with SiC fibre; and Al-3.7S Mg alloy reinforced with A1 203 fibre. The general approach was to establish a satisfactory manufacturing method for the composites before evaluating their mechanical properties. The vortex technique was used to introduce the fibres into the molten alloy. Pre-treatment of the fibres, to induce wetting, and the use of a specially designed device for fibre separation and introduction to the molten A1-ai10ys was found to be necessary so that a uniform distribution of fibres oriented in three dimensions could be achieved. The composites were squeeze cast, under conditions which were experimentally determined, to ensure the production of pore-free castings with fine equiaxed structures. The improvement in tensile strength and ductility of the cast metal, provided by squeeze casting, would be beneficial to composite properties. Composite castings, with up to 10% volume fibre, were produced with a sound structure and with fibres that were uniformly distributed and randomly oriented in three dimensions. It was found that the reaction between the fibres and the respective molten alloy must be closely controlled so that fibre reinforcement can be realised. In this respect the optimum time of contact between the fibres and the molten alloy was experimentally defined for both composite systems. The tensile properties (UTS, 0.1% proof stress, and ductility) of the fibre-free alloys were substantially improved by squeeze casting. The addition of fibre produced further substantial improvement in the tensile properties of the squeeze cast composites, in particular elastic modulus and 0.1% proof stress. Furthermore, composite properties were isotropic. The improvement in the tensile properties of composite castings (as a result of the addition of fibre) was maintained at elevated temperatures. At 250oC, castings of both composite systems with 10% (volume) fibre had 0.1% proof stress and elastic modulus values similar to those for the fibre-free castings at room temperature .. The tensile properties of the composite castings were not affected by thermal cycling (at experimental conditions). The fatigue life of the squeeze cast composite was substantially improved over and above the initial improvement in fatigue life of the fibre-free castings produced by squeeze casting. Wear of cutting tools was adversely affected by the presence of fibres

    Two-Particle Self-Consistent method for the multi-orbital Hubbard model

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    One of the most challenging problems in solid state systems is the microscopic analysis of electronic correlations. A paramount minimal model that encodes correlation effects is the Hubbard Hamiltonian, which -- albeit its simplicity -- is exactly solvable only in a few limiting cases and approximate many-body methods are required for its solution. In this review we present an overview on the non-perturbative Two-Particle Self-Consistent method (TPSC) which was originally introduced to describe the electronic properties of the single-band Hubbard model. We introduce here a detailed derivation of the multi-orbital generalization of TPSC and discuss particular features of the method on exemplary interacting models in comparison to dynamical mean-field theory results.Comment: 22 pages, 10 figure

    Limits and consistency of non-local and graph approximations to the Eikonal equation

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    In this paper, we study a non-local approximation of the time-dependent (local) Eikonal equation with Dirichlet-type boundary conditions, where the kernel in the non-local problem is properly scaled. Based on the theory of viscosity solutions, we prove existence and uniqueness of the viscosity solutions of both the local and non-local problems, as well as regularity properties of these solutions in time and space. We then derive error bounds between the solution to the non-local problem and that of the local one, both in continuous-time and Backward Euler time discretization. We then turn to studying continuum limits of non-local problems defined on random weighted graphs with nn vertices. In particular, we establish that if the kernel scale parameter decreases at an appropriate rate as nn grows, then almost surely, the solution of the problem on graphs converges uniformly to the viscosity solution of the local problem as the time step vanishes and the number vertices nn grows large
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