The range of validity of the anomalous diffraction approximation to electromagnetic scattering by a sphere.
The ranges of refractive index and particle size over which the anomalous diffraction approximation is valid to within 15%, 50%O, and 100% are mapped. The approximation is found to have a broader range of applicability for the extinction efficiency than the Rayleigh-Gans approximation. The large range of validity explains the success of schemes for determining particle size distributions of spheres from extinction measurements based on analytic inversions of formulas containing the approximation.
Bridging technique for calculating the extinction efficiency of arbitrary shaped particles.
A general bridging technique is developed to calculate the extinction efficiency of particles by combining the extended Rayleigh-Debye approximation and the modified anomalous diffraction theory. Comparisons with the exact methods are performed for spheres, spheroids, infinite cylinders, and finite cylinders. The overall features of the extinction efficiencies calculated from the new, to our knowledge, bridging method are in agreement with those calculated from the exact methods. Also discussed are accuracy of the new method and its domain of applicability. The new technique can be potentially applied to particles of virtually any shapes and sizes.
The uprising of the marginalised: a socio-economic perspective of the Syrian uprising
More than three years after the outbreak of protests in a number of Arab countries, the role of socio-economic factors in these events is attracting more attention. One of the cases that needs more research is Syria. More than three years into the Syrian uprising, the socio-economic roots of the protest movement that became one of the bloodiest civil conflicts in the history of the Middle East need to be examined. While it has been observed that the Syrian uprising, contrary to some ‘Arab Spring’ countries, has been an uprising of more marginalised social groups with a strong role played by poorer segments in the society, particularly rural and rural-to-urban migrants, the socio-economic explanation for this is still underdeveloped. This paper aims at contributing to a better understanding of this issue by examining the political and socio-economic compromise that underlined the rule of the Ba’th party in Syria for four decades and unpacking how a combination of internal and external shifts that started in the 1990s and intensified in the 2000s led to the erosion of this compromise, providing the background to the events that began in 2011.