Characteristics of a fluted nozzle gas eductor system

Cold flow tests were conducted on a four nozzle and a one nozzle gas educator system. The nozzles employed were fluted with a constant cross sectional area. The four nozzle tests used a mixing stack length-to-diameter ratio, (L/D), 1.5; the single nozzle tests used L/D ratios of2.0, 1.75, and 1.5. The total cross sectional area of the mixing stack was 2/3; for the single fluted nozzle, 2.42. Secondary pumping coefficients, mixing stack pressure distributions, and exit velocity profiles were determined. The pumping performance of the four fluted nozzle system was found to be comparable to a straight nozzle system, showing no specific advantages. The single fluted nozzle system pumping performance showed a slight improvement with increased L/D. The system performance was comparable to the four straight nozzle system at the same L/D. The peak exit velocities of the single fluted nozzle system were higher than those for the four straight and four fluted nozzle systems.http://archive.org/details/characteristicso00boykLieutenant, United States NavyApproved for public release; distribution is unlimited

Design Guidelines for True Green LEDs and High efficiency Photovoltaics Using ZnSe/GaAs Digital Alloys

In the fields of solid state lighting and high efficiency solar photovoltaics (PV), a need still exists for a material system that can target the 2.3-2.5eV energy range. The ZnSe/GaAs system is shown to have great potential. The digital alloy approach can be utilized as a well-ordered design alternative to the disordered alloy systems. The effective band-gap of the ZnSe/GaAs(001) superlattice has been studied, as a function of the constituent monolayers using tight binding. The possibility of engineering a range of band-gaps with the same material system, to achieve the optimum value for solar PV and LED applications, has been proposed