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Works: 4 works in 5 publications in 1 language and 5 library holdings
Publication Timeline
Most widely held works by HEBREW UNIV JERUSALEM (Israel) MICROWAVE DIV
Physics of vibronic transitions in the spectra of rare earth ions in crystals ( Book )
2 editions published between 1966 and 1967 in English and held by 2 libraries worldwide
Enhancement of vibronic transitions with self-trapping of the parent resonance radiation was investigated in gadolinium compounds. Optical pumping of gadolinium was tried in several host lattices for obtaining a vibronic laser. The pumping efficiency was found to be considerably below the threshold. Vibronic spectra of gadolinium assiciated with adjacent H( - ) ion in CaF2 were recently observed. The assignment of this transition and the correlation with the Infra-red absorption of the H( - ) ion is discussed. (Author)
Effects of cross-sectional area change on the speed of a shock wave ( Book )
1 edition published in 1966 in English and held by 1 library worldwide
An experimental study of the effect of convergent and divergent nozzles with area changes of 4:1, 1:4 and 1:8 on the moderate shock speed is presented. The results are compared with the theoretical predictions of the linear and steady state theories. When the experimental values are corrected for viscous effects, it is found that near the exit of the nozzle the Mach speed approximates the values of the linear theory. Far downstream the Mach speed approaches to the steady state values. Superimposed on this gradual change are maxima and minima in the Mach speed. These fluctuations are functions of P4, P1, M and the angle of the taper section. These maxima and minima can be explained to arise from interference effects between the transmitted and re-reflected shock waves. (Author)
Optical Measurements and Microwave Measurements Behind Shock Waves ( Book )
1 edition published in 1971 in English and held by 1 library worldwide
Microwave attenuation and neutral gas density profiles were measured behind shock waves in air, at initial pressure of 5 torr in the shock Mach No. range of 8 - 10. From these data, formation times of atomic oxygen and ionization relaxation times were obtained. It is shown that the formation time of atomic oxygen agrees well with different theoretical calculations. The ionization relaxation time fits the theoretical curve obtained by Lin and Fyfe. The electron peak density was found to be 2 - 3 times higher than the values calculated for thermodynamic equilibrium. The neutral gas density was measured with the aid of a simple laser interferometer. (Author)
Optical and microwave measurements behind shock waves ( Book )
1 edition published in 1968 in English and held by 1 library worldwide
The Mach velocity, shock tube attenuation and the maximum test time have been measured in two narrow shock tubes of 1 inch and 1/2 inch diameter. The apparatus is described. The results are compared with theories of Mirels, Roshko and Russel. The results are also compared with experimental results on large cross-sectional shock tubes. It is shown that for pressures of 5 Torr or less the narrow shock tube attenuation and maximum test time fits within a geometric scaling factor those of large cross-sectional tubes. At pressures of 10 Torr and higher partial turbulent flow can explain the experimental results. (Author)
English (5)
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