22,664 research outputs found
Line spread instrumentation for propagation measurements
A line spread device capable of yielding direct measure of a laser beam's line spread function (LSF) was developed and employed in propagation tests conducted in a wind tunnel to examine optimal acoustical suppression techniques for laser cavities exposed to simulated aircraft aerodynamic environments. Measurements were made on various aerodynamic fences and cavity air injection techniques that effect the LSF of a propagating laser. Using the quiescent tunnel as a control, the relative effect of each technique on laser beam quality was determined. The optical instrument employed enabled the comparison of relative beam intensity for each fence or mass injection. It was found that fence height had little effect on beam quality but fence porosity had a marked effect, i.e., 58% porosity alleviated cavity resonance and degraded the beam the least. Mass injection had little effect on the beam LSF. The use of a direct LSF measuring device proved to be a viable means of determining aerodynamic seeing qualities of flow fields
Receipt, 29 January 1866
https://egrove.olemiss.edu/aldrichcorr_d/1074/thumbnail.jp
Notropis hubbsi, a new cyprinid fish from the Mississippi River basin, with comments on Notropis welaka
http://deepblue.lib.umich.edu/bitstream/2027.42/57119/1/OP683.pd
Pressurization of Liquid Oxygen Containers Progress Report No. 7, Nov. 1963 - Nov. 1964
Pressurization of liquid oxygen containers - cryogenic fluid boiling under high and low gravity, liquid hydrogen boiling, injection cooling, and two-dimensional heat transfe
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