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Wood Storks (Mycteria americana) were followed (n = 269) from their colony in east-central Georgia to foraging sites to examine the foraging travel strategies of these birds. Most sites were relatively close to the colony (median distance = 8.8 km) requiring short travel times (median time = 22.52 min). Directness ratios (total distance flown/direct distance) for 89 mapped foraging flights suggested that storks flew relatively straight paths to feeding areas. Comparison of flight (air) speeds determined from this data with speeds determined from energetics models suggested that storks minimized flight energy costs rather that maximized range during foraging travel. Estimated energetic costs of flapping and soaring modes of flight were 204.8 W and 18.1 W, respectively. Seasonal analyses indicated that storks employed soaring flight more frequently in the latter half of the breeding season when they traveled to more distant sites. Energetic costs did not vary seasonally due to the increase in use of the energetically conservative soaring mode of travel on the longer flights. Observations at the colony indicated that foraging trip durations were constant throughout the season and that parents met increased nestling food demand by increasing the frequency of foraging trips.

Argon gas puff experiments on a 3-4 MA generator show that the K-shell x-ray yield is optimized for a 2.5 cm initial diameter and 110 ns implosion time. By varying the driver current, the K-shell yield varies from 13 to 18 kJ following a current to the fourth power scaling. Comparisons of these experimental data to one-dimensional radiation-hydrodynamic simulations with and without enhanced transport coefficients show that the measured K-shell yields exceed those predicted based solely on kinetic energy input.

The K-shell x ray yields from argon gas puff Z pinches are observed to increase from 3.5±1.0 kJ to 13±1.0 kJ when inwardly tilted nozzles are used on a 6 TW, 4 MA generator. This increase is associated with the elimination of the zipper effect and the achievement of higher density plasmas, as confirmed by x-ray diagnostics. Two-dimensional (2-D) magnetohydrodynamic modeling of the gas puff implosions indicates that the collapsing shell reaches a higher density and smaller diameter when the axial zipper is eliminated. The calculations show that axial mass flow in the zippering cases result in nonhollow collapses which limit the final pinch radii and densities. The calculations also indicate that narrower nozzle exits contribute to increasing the assembled plasma density.

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