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An investigation was conducted to determine the effect of varying the jet exhaust ratio of specific heats, gas constants, and temperatures on jet interference on afterbody drag. Jet exhaust simulation parameters were also evaluated. In addition to air, three other exhaust gases, each with a different value of each of the gas parameters, were tested. The range of the ratios of specific heats, gas constants, and total temperatures of the four gases are identified. Tests were made using a single nacelle model with afterbodies having boattail angles of 10 degrees and 20 degrees with sonic and Mach two jet exits. Wind tunnel tests were conducted through a Mach number range of 0.60 to 1.20 and a Reynolds number per meter from 10.06 million to 14.05 million.

Electrons interaction with impurities and longitudinal optical phonon in metal-insulator- semiconductor tunnel junctions

Use of luminescence in irradiated silicon to determine the thermal stability of the defects responsible for the recombination. It is found that the defect responsible for the zero-phonon line at 0.97 eV has an annealing behavior similar to that of the divacancy and that the zero-phonon line at 0.79 eV anneals in a manner similar to the G-15 or K-center. Annealing at temperatures up to 500 C generates other defects whose luminescence is distinct from that seen previously. Addition of lithium to the material produces defects with new characteristic luminescence. Of particular importance is a defect with a level at E sub g -1.045 eV.

Demonstration that luminescence in irradiated silicon consists of a spectral group between 0.80 and 1.0 eV which seems to be independent of impurities, while a lower energy group between 0.60 and 0.80 eV is seen only in pulled crystals. The small halfwidth and temperature dependence of the sharp zero-phonon lines observed in these spectra indicate that the luminescence arises from a bound-to-bound transition. A model is proposed for the transition mechanism. Stress data taken on the 0.79-eV zero-phonon line in pulled crystals can be fit by either a tetragonal 100 (in brackets) defect symmetry or by conduction-band splitting effects. It is suggested that the 0.79-eV zero-phonon line and the 0.60- to 0.80-eV spectral group arise from the EPR G-15 center. Stress data on a zero-phonon line at 0.97 eV associated with the 0.80- to 1.0-eV spectral group can be explained by a trigonal 111 (in brackets) defect. The divacancy is tentatively suggested as responsible for this luminescence spectra.

Tunneling in boron doped p-type silicon metal-semiconductor and MIS tunnel junctions

Tunneling electron and local mode phonon interaction in MIS n-type semiconductors

Jet effects on boattail axial force of conical afterbodies at subsonic and transonic speeds

Vacuum cleavage device for producing small area evaporated metal semiconductor contacts free from oxygen or other contamination

Recombination luminescence and electron tunneling in silicon

Irradiation effects on semiconductor properties, luminescence, and p-i-n diode electrical properties

Potassium chloride crystal color centers as photochromic memory device in computer systems

High resolution luminescence spectra of electron irradiated silicon

Bending mode vibratory response of supported and sleeved ducts with fatigue and alloy studies

Zirconium-based alloy brazing of internal fins of Cb-1Zr foil to Cb-1Zr heat receiver tubes

Luminescence spectra due to radiative recombination of optically injected carriers in Co 60 gamma ray and neutron irradiated Si at low temperature

Effect of geometry of conical afterbodies on base drag at subsonic and transonic speeds

Theoretical models and experiments on optimization of duct assemblies for vibration

Effects of high energy radiation on properties of silicon

Process developed for brazing niobium-zirconium alloys for heat exchanger tube fabrication

Semiconducting Si luminescence arising from recombination of holes and electrons at point defects produced by neutron or gamma ray irradiation

Recombination luminescence of irradiated silicon, and hole-optical phonon interaction in degenerate silicon

Radiation effects on semiconductors, and recombination lifetimes in gamma-irradiated, boron-doped silicon

Passive nonmetallic gyroscopic earth satellite for measuring in-plane precession predicted by general relativity

Annealing of fast neutron damage in impurity conducting n-type Ge, noting small activation energy in resistivity below 10 degrees K

Recombination luminescence in Czochralski silicon

Electron decay rate and absorption cross sections for electron holes and recombination in gamma irradiated n-type silicon

Annealing of neutron irradiation induced changes in impurity conduction in Sb-doped Ge

Radiation effect on recombination luminescence and tunneling in semiconductors

Compensation dependence of impurity conduction in n-type germanium containing antimony atoms

Annealing of neutron-irradiation-induced changes in impurity conduction in antimony-doped germanium