Search

A 57-year-old rural Negro of unusually rugged and independent disposition, owner of a 150-acre farm, went through a series of depressing incidents prior to the build-up of hypomanic activity which terminated with psycholeptic suddenness in the outbreak of a definite manic attack. In the excitement he praised God, sang and shouted, with the feeling of satisfaction and even power through his allegiance to God. In so doing he obviously was acquiring a position above that of any person in the community, even in the country, if not in the world, without in any way challenging the social structure of the society in which he was living, since religious exaltation is one of the few outlets he has always been encouraged to find. Treatment included a period of rest in the hospital, during which the patient gave an account of his whole life, including the excitement, and this story was recorded on a series of sound records which were later edited. After return to the farm, the acute phases of the psychosis were re-e...

Mathematical models of thermal and shot noise characteristics of transistors are adequate for the determination of the optimum operating point and source impedance for the mid-frequency region. However, in the case of l/f noise, which occurs at low frequencies and has a spectral distribution proportional to l/f^{n} , models presently available do not describe the phenomenon sufficiently for practical design purposes. This paper describes an experimental approach to the determination of optimum operating point and source impedance for transistor circuits in applications where l/f noise predominates. Results of a number of tests which measure the noise spectrum as a function of operating point and source impedance are described. Results of such tests are presented as parametric plots of noise factor versus frequency, and conclusions are drawn as to the choice of parameters for optimum noise performance at low frequencies. A description of the special measurement techniques is included. A procedure is developed for rapid determination of the entire noise spectrum of a transistor for practical design purposes.

An experimental program has been conducted to collect information concerning the correlation bandwidth of the tropospheric scatter medium in the 5-Gc region. By transmitting bursts on five different frequencies, data were obtained on separations of 1.5, 3.0, 4.5, and 6.0 Mc for a 100-mile path. An IBM 7090 computer was programmed to calculate the cross-correlation coefficients between the pairs of frequencies. The experimental results are in agreement with theory, and indicate that frequencies as closely spaced as 1.5 Mc can have correlation coefficients of the order of 0.4.

The Kozeny equation relating specific surface and permeability of a bed of unconsolidated particles has been shown to be applicable to fibrous materials such as glass, wool, and celanese. The diameters of the constituent fibre may be as small as 0.0006 cm., while their ratio of length to diameter may be indefinitely large. Uniformity of size or of packing is not essential.

Extensive field programs were undertaken in Alaska during the winters of 1952-1954 to determine the causes of ice-fog formation. Ice fog forms at temperatures near -30 C and below in populated areas and is particularly troublesome at military installations. It poses no threat to health but seriously restricts visibility. The fog is a direct result of supersaturation of the cold air with water vapor from man-made sources. The only methods of curtailing its formation appear to be restricting vapor emission into the air or confining emission to selected fall stacks. Microphotographs of ice fog particles collected at various temperatures are included.