This technical report represents a brief survey of work by this project on the effects of ultraviolet radiation (UV) on certain of the photochemical and metabolic properties of rhubarb chard and sugar beet (Beta vulgaris). These plants were selected for this work because for some years they have been used as sources of chloroplasts for Hill reaction studies in this laboratory. Some of this work has appeared as a brief paper.

Fused uranium dioxide was separated into fractions of varying particle size by air separation. Specimens of the nominal size of 1/8 by 1/4 by 1½ in. were formed by hydrostatic pressing, firing, and lapping. Specimens prepared from the 0 to 5 μ fraction were the strongest and most dense. The room-temperature density was about 92% of theoretical and the room-temperature flexural strength was about 12,000 1b. per sq. in. When tested at 1000°C., the strength was about 18,000 1b. per sq. in. The flexural strength of specimens decreased and their density decreased as the starting particle size was increased. The crystallization of the urania fragments which had occurred during the firing treatment was observed.

During this period a prototype gamma ray detection system was assembled and data was obtained on samples of beryllium salts on filter paper under a variety of conditions. Ordinarily either a scaler-register combination or the CRM-recorder combination would be sufficient for obtaining data. Both units have been used here in order to utilize the particular advantages of each system. The scaler-register unit was employed for obtaining precise data over short intervals while the CRM-recorder was used to maintain a check on stability over longer intervals of time.

Part A. The major effort during the past year has been the construction of a suitable vacuum furnace for studying the effects of temperature and pressure on the wettability of metals by glass. A systems was completed that was capable of subjecting test combinations up to temperatures of 1400 degree C at a working pressure of 1 x 10(-5) mm. of Hg. Part B. A compound, identified by X-ray analysis as sodium meta tantalate (na2Ta2O6), was found at the interface between a sodium silicate glass and tantalum metal which had been heated in vacuum to 1000 degree C. thermodynamic calculations, followed by further experimental evidence, were used to determine the chemical reaction between tantalum and sodium silicate which resulted in the formation of Na2Ta3O6. the compound was synthesized by other methods, and its structure investigated.

1) The technical details of controlled experiments with iontophoresis of thorium X solutions are described. 2) Experiments carried out on living human skin in situ demonstrate that Iontophoresis of weak solutions of thorium X will increase its biologic effects as judged by erythema and pigmentation, and cause greater penetration as shown by autoradiography. 3) The possible relationship between increased penetration of thorium X and increased clinical biologic effects is discussed. 4) Some possible clinical applications of the Iontophoresis of thorium X to enhance its therapeutic effectiveness are mentioned.

The primary purpose of this contract is to develop and exploit techniques for the precision measurement of nuclear energy levels by the spectroscopic study of gamma-rays emitted during the decay of radioisotopes, (1) by the use of a high resolving power curved crystal focusing spectrometer to study wavelengths and intensities of gamma-rays themselves, (2) by means of a precision beta-ray spectrometer to study the conversion lines from gamma-rays both by internal conversion and with external converters.