The Pan-African Movement and American Black Political Fiction, 1920s to 1950s: Themes of Alienation

This paper focuses on the role of the writer as a social activist. Accordingly, I examine novelist/essayists who published during the Harlem Renaissance period 1920 to 1930 and in some cases beyond. I am interested in part in the Pan-African movement as it impacted on this era of Afro-American history. The central question explored is what are some of the dynamics that exist between the writer, movement elites, movement rank-in-file, and the broader Afro-American community? The central focus is on the kind of interactions that take place between the writer as a political activist, movement elites, and movement activists. The following writers seem to reflect this particular period -- W.E.B. Du Bois, Claude McKay, Langston Hughes among others

Proposed acousto-optic filter

Narrow band optical filter is electronically tunable over a large wavelength region. The filter utilizes collinear acousto-optic diffraction in an optically anisotropic media

On the adjoint representation of sln\mathfrak{sl}_n and the Fibonacci numbers

We decompose the adjoint representation of $\mathfrak{sl}_{r+1}=\mathfrak {sl}_{r+1}(\mathbb C)$ by a purely combinatorial approach based on the introduction of a certain subset of the Weyl group called the \emph{Weyl alternation set} associated to a pair of dominant integral weights. The cardinality of the Weyl alternation set associated to the highest root and zero weight of $\mathfrak {sl}_{r+1}$ is given by the $r^{th}$ Fibonacci number. We then obtain the exponents of $\mathfrak {sl}_{r+1}$ from this point of view.Comment: 9 page

Historical regulation of Victoria's water sector: A case of government failure?

This paper analyses the role of government failure in Victoria’s water sector between 1905 and 1984 as evidenced in the rise of in-stream salinity. It will be shown that high levels of salinity can, in part, be attributed to regulatory failure for two reasons. First, the method of water allocation, a compulsory minimum charge with the marginal cost of water being zero, encouraged over watering, resulting in increased water tables via groundwater recharge. Second, the government did not provide adequate finance for construction of appropriate removal of saline drainage water, and thereby allowed increasing in-stream salinity.externalities, government failure, institutions, salinity, Resource /Energy Economics and Policy,

Dark Matter Halos in Galaxies and Globular Cluster Populations

We combine a new, comprehensive database for globular cluster populations in all types of galaxies with a new calibration of galaxy halo masses based entirely on weak lensing. Correlating these two sets of data, we find that the mass ratio $\eta \equiv M_{GCS}/M_{h}$ (total mass in globular clusters, divided by halo mass) is essentially constant at $\langle \eta \rangle \sim 4 \times 10^{-5}$, strongly confirming earlier suggestions in the literature. Globular clusters are the only known stellar population that formed in essentially direct proportion to host galaxy halo mass. The intrinsic scatter in $\eta$ appears to be at most 0.2 dex; we argue that some of this scatter is due to differing degrees of tidal stripping of the globular cluster systems between central and satellite galaxies. We suggest that this correlation can be understood if most globular clusters form at very early stages in galaxy evolution, largely avoiding the feedback processes that inhibited the bulk of field-star formation in their host galaxies. The actual mean value of $\eta$ also suggests that about $1/4$ of the \emph{initial} gas mass present in protogalaxies collected into GMCs large enough to form massive, dense star clusters. Finally, our calibration of $\langle \eta \rangle$ indicates that the halo masses of the Milky Way and M31 are $(1.2\pm0.5)\times 10^{12} M_{\odot}$ and $(3.9\pm1.8)\times 10^{12} M_{\odot}$ respectively.Comment: 6 pages, ApJL in pres

Automated Design of Tissue Engineering Scaffolds by Advanced CAD

The design of scaffolds with an intricate and controlled internal structure represents a challenge for Tissue Engineering. Several scaffold manufacturing techniques allow the creation of complex and random architectures, but have little or no control over geometrical parameters such as pore size, shape and interconnectivity- things that are essential for tissue regeneration. The combined use of CAD software and layer manufacturing techniques allow a high degree of control over those parameters, resulting in reproducible geometrical architectures. However, the design of the complex and intricate network of channels that are required in conventional CAD, is extremely time consuming: manually setting thousands of different geometrical parameters may require several days in which to design the individual scaffold structures. This research proposes an automated design methodology in order to overcome those limitations. The combined use of Object Oriented Programming and advanced CAD software, allows the rapid generation of thousands of different geometrical elements. Each has a different set of parameters that can be changed by the software, either randomly or according to a given mathematical formula, so that they match the different distribution of geometrical elements such as pore size and pore interconnectivity. This work describes a methodology that has been used to design five cubic scaffolds with pore size ranging from about 200 to 800 µm, each with an increased complexity of the internal geometry.Mechanical Engineerin