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As part of a research program on the microwave dielectric properties of compressed gases, absorption in NH3, arising from the inversion band at 1.25 cm, was studied at a wavelength of 11 cm. Especially careful measurements made at a pressure of 10 cm Hg, which from previous evidence is just below the region where an apparent shift of the inversion lines toward zero frequency begins, gave an absorption...
This work is an extension of that reported in 1950 by E. L. C. Larson and G. M. L. Sommerman. At that time, it was shown that photographic records of impulse ionization in liquids could be obtained, by placing dry photographic paper and impregnated paper pressboard between; disk electrodes, immersing them in the liquid to be tested, and applying a single impulse voltage wave of a magnitude somewhat...
From large single crystals of ice, grown by means of the earlier published method1, square plates were cut with the major surfaces either parallel or perpendicular to the optic c axis. The dielectric constants were then measured as a function of the temperature and of the frequency, as well as the loss angles. The dielectric constant εc measured in the direction of the c axis was found to be slightly...
At last year's Conference two papers were presented by A. J. Warner and H, G. Nordlin of Federal Telecommunication Laboratories covering research work on the effects of ionizing radiation on high quality insulating materials. This paper summarizes some of the findings made in a continuation of the same studies. The work reported here was sponsored by the Signal Corps Engineering Laboratories, Fort...
A study has been made of insulation deterioration treated as a time rate phenomenon. It is shown that certain dielectric properties (i.e., dielectric strength and dissipation factor) of typical high temperature transformer insulations deteriorate, with time and temperature, in a manner which indicates the presence of two first order chemical reactions. The effects on the properties, due to these reactions...
The experiments described here give further confirmation of the fact that microbiological failure of rubber insulation is caused by the penetration of certain soil fungi.
The requirements of the Armed Services for dielectric materials at times are very specific. At times they appear contradictory. There are times when they appear to he farfetched and philosophical.
The optimum Q values of cup core inductors of various sizes utilizing several commercial ferrite materials have been determined empirically by variation of the effective permeability (air-gap) and the coil winding data (number of turns, wire size, degree of stranding). The results are presented in the form of Q-contours plotted versus inductance and frequency. In each individual case, the highest...
Using very good BaTiO3 single crystals, we have investigated the arrangements and movements of the domains. Besides the well known 90° walls we have observed 180° walls very clearly. A 180° wall forms the boundary between two domains polarized at 180° to each other (antiparallel). It turns out, that every so called single domain crystal consists of hundreds of small antiparallel domains, Applying...
Ceramics technology is more an art than a science, due to the complexity of chemical systems involved. Even with simple bodies there are major constituents which form solid solutions, mixtures and glassy phases. The major constituents bring in impurities which also form solid solutions, mixtures and glasses; therefore, it is not surprising that the combinations often become too complex for scientific...
It has been reported-recently by Salvage (1) that the electric strengths of liquid, straight-chain hydrocarbons increase with increase in molecular weight from n-pentane through n-nonane. The purpose of the present work is to verify and investigate more carefully this behavior, and to interpret the results, if possible, in terms of the physical properties of the hydrocarbons.
This study was carried out in order to establish: the nature of ions in oxidized hydrocarbons, since it was realized that these oxidative ions are different from, those present in a cid-amine-phenol solutions previously studied. As suitable material for the present study oxidized N-heptaldehyde solutions in oil and xylene were chosen; mild oxidation of such solutions yielded samples having marked...
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