David W. Jackson

Learn More
To assess the role of thermal contraction-crack polygons (sublimation polygons) in modulating sublimation of buried glacier ice in Antarctica, we applied a 2D numerical model using COMSOL Multiphysics that calculates the rate and spatial variability of vapour diffusion through porous media. Specifically, we examined vapour transport through Granite drift, a(More)
The procedures for calculating illuminance by Average Lumen and Point Lighting are described. The normal procedures of a design office in performing lighting calculations are described, showing the applicability of programrable calculators to the repetitive calculations required for optimizing design. Five programs are described, some developed for engineer(More)
The purpose of this article is to re-acquaint the reader with the etiology of Class III malocclusions, review the use of the Reverse-Pull Headgear (Profile Enhancer) in Class III patients, understand the limitations in older patients, and provide alternative treatment to finish the case. Often orthodontic treatment of certain patients requires combinations(More)
The results reported in this paper suggest that capacitor protection of large AC motors may not be adequate to protect against motor starting switching surges when the length of the leads connecting the capacitor to the machine terminals and to ground are substantial. Accordingly, it is shown that the magnitude and shape of the switching surges appearing in(More)
Long-range holographic experiments have been performed over distances as large as 12 km. Holograms and images of retroreflector and Scotchlite objects were obtained. The reference wave was supplied by a retroreflector placed next to the object, and the source of illumination was a Q-switched ruby laser. Resolutions obtained varied with atmospheric seeing(More)
A survey of manufacturers and users of surge protective capacitors and arresters for rotating machines was conducted to obtain device failure data for comparison with failure statistics on rotating machine insulation. Answers to two questions were sought. (1) Do protective devices reduce or increase the overall machine failure rate? (2) Is there a cost or(More)
  • 1