Emergence of turbulence in an oscillating Bose-Einstein condensate

We report on the experimental observation of vortices tangle in an atomic BEC of Rb-87 atoms when an external oscillatory perturbation is introduced in the trap. The vortices tangle configuration is a signature of the presence of a turbulent regime in the cloud. We also show that this turbulent cloud has suppression of the aspect ratio inversion typically observed in quantum degenerate bosonic gases during free expansion. Instead, the cloud expands keeping the ratio between their axis constant. Turbulence in atomic superfluids may constitute an alternative system to investigate decay mechanisms as well as to test fundamental theoretical aspects in this field.Comment: accepted for Phys. Rev. Let

From Rodeos to Indie Rock: The Economic and Fiscal Impacts of Selected Cultural Events in Denton, Texas

This report discusses the economic and fiscal impacts of selected cultural events in Denton, Texas

Route to turbulence in a trapped Bose-Einstein condensate

We have studied a Bose-Einstein condensate of $^{87}Rb$ atoms under an oscillatory excitation. For a fixed frequency of excitation, we have explored how the values of amplitude and time of excitation must be combined in order to produce quantum turbulence in the condensate. Depending on the combination of these parameters different behaviors are observed in the sample. For the lowest values of time and amplitude of excitation, we observe a bending of the main axis of the cloud. Increasing the amplitude of excitation we observe an increasing number of vortices. The vortex state can evolve into the turbulent regime if the parameters of excitation are driven up to a certain set of combinations. If the value of the parameters of these combinations is exceeded, all vorticity disappears and the condensate enters into a different regime which we have identified as the granular phase. Our results are summarized in a diagram of amplitude versus time of excitation in which the different structures can be identified. We also present numerical simulations of the Gross-Pitaevskii equation which support our observations.Comment: 6 pages, 3 figure

Assessment of the Potential Fiscal Impacts of Existing and Proposed Transit-Oriented Development in the Dallas Area Rapid Transit Service Area

This report by the University of North Texas Center for Economic Development and Research gives an assessment of the fiscal impacts of transit-oriented development associated with development of the Dallas Area Rapid Transit (DART)light rail system. This analysis considers development near existing and planned light rail stations. The findings support the conclusion that the transit-oriented developments associated with DART Rail stations offer substantial fiscal impacts for local taxing entities

The Healthcare Services Industry in Tarrant County: Industry Overview and Projected Employment Growth in Specified Occupations

The purpose of this report, by the University of North Texas Center for Economic Development and Research, is to offer an assessment of the current status of the healthcare services industry in Tarrant County. Also, to forecast demand for training in these specified occupations over the next several years

Controlled Anisotropic Deformation of Ag Nanoparticles by Si Ion Irradiation

The shape and alignment of silver nanoparticles embedded in a glass matrix is controlled using silicon ion irradiation. Symmetric silver nanoparticles are transformed into anisotropic particles whose larger axis is along the ion beam. Upon irradiation, the surface plasmon resonance of symmetric particles splits into two resonances whose separation depends on the fluence of the ion irradiation. Simulations of the optical absorbance show that the anisotropy is caused by the deformation and alignment of the nanoparticles, and that both properties are controlled with the irradiation fluence.Comment: Submitted to Phys. Rev. Lett. (October 14, 2005

The Current and Potential Economic and Fiscal Impacts of Texas' Moving Media Industry

This report compares the film industry incentive programs of other states with the Texas incentive program and examines their respective economic and fiscal impacts. In Texas, the economic impact of the moving media industry approached $345 million in 2007. This report also identifies strategies proposed to enhance Texas' future competitive position in the moving media industry

Economic and Fiscal Impacts of DFW International Airport's Disadvantaged, Minority- and Women-Owned Business Enterprise: Detailed Findings and Updates

This report, by the University of North Texas Center for Economic Development and Research, updates the 2004/2005 analyses of the regional economic activity generated by Disadvantaged, Minority- and Women-Owned Business Enterprise (DMWBE) contractors and vendors operating at Dallas/Fort Worth International Airport (DFW Airport)

Three-vortex configurations in trapped Bose-Einstein condensates

We report on the creation of three-vortex clusters in a $^{87}Rb$ Bose-Einstein condensate by oscillatory excitation of the condensate. This procedure can create vortices of both circulation, so that we are able to create several types of vortex clusters using the same mechanism. The three-vortex configurations are dominated by two types, namely, an equilateral-triangle arrangement and a linear arrangement. We interpret these most stable configurations respectively as three vortices with the same circulation, and as a vortex-antivortex-vortex cluster. The linear configurations are very likely the first experimental signatures of predicted stationary vortex clusters.Comment: 4 pages, 4 figure