Light dynamics in glass-vanadium dioxide nanocomposite waveguides with thermal nonlinearity

We address the propagation of laser beams in Si02-VO2 nanocomposite waveguides with thermo-optical nonlinearity. We show that the large modifications of the absorption coefficient as well as notable changes of refractive index of VO2 nanoparticles embedded into the SiO2 host media that accompany the semiconductor-to-metal phase transition may lead to optical limiting in the near-infrared wave range.Comment: 13 pages, 3 figures, to appear in Optics Letter

The Bolivarian Dream: ALBA and the Cuba-Venezuela Alliance

This thesis seeks to answer why the Bolivarian Alliance for the Peoples of Our America (ALBA) has failed to achieve its two major goals: to create a socialist alternative to neoliberalism and foster mutual cooperation among the members. Important constructivist works from Nicolas Onuf and Alexander Wendt were used throughout. Emphasis is given to the debate between social construction and material reality that has hindered ALBA’s goals. Three reasons led to why ALBA could not achieve its two major goals. First, the successors to the founding leaders of ALBA did not share the same sympathy toward socialism, and instead carved their own foreign policy. Second, ALBA did not create a socialist alternative since its programs were plagued by ill-defined rules. Third, China, Iran, and Russia, were pulled to ALBA due to the influence of Venezuela. These actors related to ALBA members on a bilateral basis, which hurt ALBA’s mutual cooperation

Codimension one Ricci soliton subgroups of nilpotent Iwasawa groups

Any expanding homogeneous Ricci soliton (in particular any homogeneous Einstein manifold of negative scalar curvature) can be obtained, up to isometry, from a Lie subgroup of a nilpotent Iwasawa group $N$ whose induced metric is a Ricci soliton. By nilpotent Iwasawa group we mean the nilpotent Lie group $N$ of the Iwasawa decomposition associated with a symmetric space of non-compact type. Motivated by this fact, in this paper we classify codimension one Lie subgroups of any nilpotent Iwasawa group $N$ whose induced metric is a Ricci soliton

When Lenders Can Legally Provide Loans with Effective Annual Interest Rates Above 1,000 Percent, Is it Time for Congress to Consider a Federal Interest Cap on Consumer Loans?

The question of whether interest rates should be regulated for the good of society has been debated by secular and religious authorities for millennia. Restrictions on the highest rate of interest allowed by law (if any) are generally set by the states. In the U.S., whether citizens are protected against unreasonably high interest rates is generally a matter for state legislatures to decide. In this article, the current laws of the 50 states and the District of Columbia are examined with regards to the issue of usury, as well as the challenges posed by federal law for states who wish to protect their citizens against unreasonably high interest rates. Special attention is paid to payday loan providers and the way that these have used loopholes in federal law to effectively undermine state interest cap regulations. Finally, the question of whether Congressional action is needed is answered