2D Pulses using spatially dependent frequency sweeping

Strongly driven frequency-sweeping events in plasmas.

A generic model of a kinetic plasma formed from a source and sink is presented which without instability would form a strongly unstable state due to a single mode. Instead, the resulting wave-particle resonant interaction maintains the distribution near a marginally stable state through the continual production of fast frequency-sweeping modes that sweep unidirectionally (upward in our case) th...

Formant frequency analysis of children's spoken and sung vowels using sweeping fundamental frequency production.

High-pitched productions present difficulties in formant frequency analysis due to wide harmonic spacing and poorly defined formants. As a consequence, there is little reliable data regarding children's spoken or sung vowel formants. Twenty-nine 11-year-old Swedish children were asked to produce 4 sustained spoken and sung vowels. In order to circumvent the problem of wide harmonic spacing, F1 ...

Dimensional Metrology and Frequency Sweeping Interferometry

Frequency Sweeping of Phase Space Structures

Holes and clumps, spontaneously formed in the nonlinear development of a single mode driven by a weakly destabilizing kinetic distribution function in a dissipative medium, were expected to persist for an appropriate collisional time scale. However, Fokker-Planck calculations for the nonlinear system abruptly break down in the course of the calculation for some initial conditions. We nd that th...

Improved 3D Spin-Echo Imaging Using Frequency-Swept Pulses

J-Y. Park, O. H. Gröhn, M. Garwood Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota, Minneapolis, MN, United States, A.I.Virtanen Institute for Molecular Sciences, University of Kuopio, Kuopio, Finland Introduction: Frequency-modulated (FM) pulses, including adiabatic full-passage (AFP) pulses, are sometimes preferred for selective refocusing in spin-e...