Submitted to Illinois Inst. of Tech., Chicago. A He/sup 3/ cryostat was built to measure the specific heat of rare earth metals which have a component, at low temperatures, attributable to the electrons in the incomplete 4f shell. The specific heat of dysprosium from 0.4 to 4.2 deg K was measured. Pertinent theories about specific heats are outlined. The apparatus included the cryostat, vacuum and He/sup 3/ systems, calorimeter, carbon thermometer, heater, and magnetic thermometer. The experimental procedure is described and results are presented in graphic and tabular form. The specific heat rose sharply below 1 deg K. An anomalous hump was centered about 2.35 deg K. (M.C.G.)

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Test results are presented that show that a strong concrete weighing approximately 185 lb/ft/sup 3/ can be made using water, waste lead slag, and Ciment Fondu. Feasibility, materials, mortar tests, concrete tests, and Ciment Fondu concretes are discussed. A 24-in.-thick concrete shield wall would have to be increased in thickness by 5 in. if slag concrete is used in place of barytes or magnetite concrete. On a pound-for-pound basis, the waste lead slag concrete materials were 30% cheaper than barytes and magnetite concrete materials. (M.C.G.)

Polycrystalline aluminum-copper alloys containing 4 and 5% copper were given heat treatments designed to develop dispersions of Al/sub 2/Cu precipitate particles of various sizes and distributions. Tensile tests were performed on the dispersion hardened alloys at 4.2, 77, 90 and 114 deg K to determine the strain rate and temperature dependence of the flow stress. The intersection analysis of the tensile data showed that the dispersed particles significantly increase the average effective forest dislocation density produced for a given amount of strain. The increased dislocation density was found to be in qualitative agreement with selected electron-microscope observations of the deformed structure of the alloys. Estimates of contributions to the flow stress arising from effects coincident with the intersection of dislocations and those associated with the build-up of long range stress fields were made. The major strengthening contribution of the dispersed particles during plastic deformation is shown to be due to an increase in the dislocation density associated with relatively high density tangles of dislocations observed to be localized near particles and groups of particles. (auth)

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Thesis submitted to Univ. of Tennessee by L. C. Emerson. An experimental investigation of the visible and ultraviolet light emitted when a charged particle moves across a boundary between two media with different dielectric properties was carried out. The spectral distributions of the light from evaporated foils of copper, germanium, silver, tin, and antimony bombarded by a 1.5-microamp beam of electrons were measured as a function of electron energy between 25 and 100 kev. The analysis was carried out with a Seya-Namioka vacuum ultraviolet spectrometer, Glan-Foucault prism polarizer, and a quartz- window photomultiplier. Calibration of the optical system with a NBS tungsten filament lamp enabled the intensity measurements to be carried out on an absolute basis. The experimental results for light polarized parallel to the plane containing the photon and the electron were compared with the calculated intensity of transftion radiation, and in general the agreement was found to be excellent. The component of the photon intensity polarized perpendicular to this plane was compared with the calculated intensity of the optical portion of the bremsstrahlung spectrum. The predicted dependence on electron energy, photon wavelength, and foil thickness was observed although the measured yield was higher than that predicted by theory. …