We construct a variety of novel localized topological structures in the 3D discrete nonlinear Schrödinger equation. The states can be created in Bose-Einstein condensates trapped in strong optical lattices and crystals built of microresonators. These new structures, most of which have no counterparts in lower dimensions, range from multipole patterns and diagonal vortices to vortex "cubes" (sta...

We have combined a novel low temperature positioning mechanism with a single-chip miniature superconducting quantum interference device ~SQUID! magnetometer to form an extremely sensitive new magnetic microscope, with a demonstrated spatial resolution of ;10 mm. The design and operation of this scanning SQUID microscope will be described. The absolute calibration of this instrument with an idea...

We demonstrate a new principle of optical trapping and manipulation increasing more than 1000 times the manipulation distance by harnessing strong thermal forces while suppressing their stochastic nature with optical vortex beams. Our approach expands optical manipulation of particles into a gas media and provides a full control over trapped particles, including the optical transport and pinpoi...

We investigate the structure of trapped Bose-Einstein condensates (BECs) with long-range anisotropic dipolar interactions. We find that a small perturbation in the trapping potential can lead to dramatic changes in the condensate's density profile for sufficiently large dipolar interaction strengths and trap aspect ratios. By employing perturbation theory, we relate these oscillations to a prev...

We introduce the concept of multipole spatial optical vector solitons associated with higher-order guided modes trapped by a soliton-induced waveguide in a bulk medium. Such stationary localized waves include previously predicted vortex- and dipole-mode vector solitons and also describe new higher-order vector solitons and necklace-type beams. We present the theoretical and experimental results...

The advection of passive tracers in an oscillating vortex chain is investigated. It is shown that by adding a suitable perturbation to the ideal flow, the induced chaotic advection exhibits two remarkable properties which do not hold in the case of a generic perturbation: Particles remain trapped within a specific domain bounded by two oscillating barriers (suppression of chaotic transport alon...

We study vortex clustering in type II Superconductors. We demonstrate that the “second peak” observed in magnetisation loops may be a dynamical effect associated with a density driven instability of the vortex system. At the microscopic level the instability shows up as the clustering of individual vortices at (rare) preferential regions of the pinning potential. In the limit of quasi-static ra...

The liner of a gas turbine combustor is a very flexible structure that is exposed to the pressure oscillations that occur in the combustor. These pressure oscillations can be of very high amplitude due to thermoacoustic instability, when the fluctuations of the rate of heat release and the acoustic pressure waves amplify each other. The liner structure is a dynamic mechanical system that vibrat...

Title of Document: Investigation of Colorless Distributed Combustion (CDC) with Swirl for Gas Turbine Application Ahmed Essam ElDin Khalil Hasan, PhD, 2013 Directed By: Dr. Ashwani K. Gupta Distinguished University Professor Department of Mechanical Engineering Colorless Distributed Combustion (CDC) with swirl is investigated for gas turbine engine applications due to its benefits for ultra-low...