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Shipping cans containing product from plant runs completed in the latter half of April and in May showed, in general, definitely higher levels of radiation than had been observed previously. Likewise, containers for the transfer of the F-10-P solution from the 224 Bldg. to 231 Bldg. (during May) exhibited higher radiation levels than could be attributed to higher power levels and increased batch sizes. These higher radiation levels were indicative that some radioactive element (or elements) was present in an amount greater than previously as would be expected from the shorter cooler periods, or that decontamination of elements previously present was less complete. It was considered essential to identify the source of these radiations and the cause for their presence has been investigated. The radioactive contaminant present in the final product has been identified rather definitely as Np{sup 239} which has 2.3d half-life a 0.25 MeV gamma ray and a weak beta ray. The amount of Np has increases as a result of the brand toward shorter cooling periods and the law decontamination factor for Np in the Separation Process.

This report presents a brief synopsis of an investigation of unusual incidents at the 100-B and 100-F areas at HAPO. (CBS)

Abstract. The separation of uranyl nitrate from aqueous solutions of 0.635 M thorium nitrate, 3 M nitric acid and 3 M calcium nitrate by extraction with organic solvents has been investigated. Solvents which gave good separations were 2-tthyl hexyl acetate, ethyl benzoate, n-butyl either and beta-beta- dichloroethyl ether. In general, higher esters, ethers and alcohols are better for separating uranium from thorium that the lower homologues. Several solvents were tested at lower nitric acid concentrations. Dibutyl cellosolve gave a very good separation when the solution was 0.1 M nitric acid. Of the solvent mixtures studied that of equal parts of n-butyl ether and dibutyl cellosolve gave a good separation.

Introduction. It has been known for a long time that thorium is precipitated by oxalic acid in acid solutions, but a survey of the literature showed no study of the limits of the acidity and oxalic acid excess which yield quantitative results. V. I. Spitzin reports on the solubility of thorium oxalate in varying concentrations of several acids, but the effect of an excess oxalic acid is not included. Since solutions are sometimes presented for analysis that contain more than the recommended two per cent mineral acid, it would be advantageous to be able to quantitatively remove the thorium without otherwise altering the solutions. This was especially of interest in solutions containing bismuth, since it was hoped that some amounts of thorium could be precipitated in nitric acid solutions containing large quantities of bismuth. In removing the bismuth, first by a bismuth oxychloride precipitation, thee is every opportunity for carrying of the thorium.

"A critical review of literature bearing on the autoignition and detonation-wave theories of spark-ignition engine knock and on the nature of gas vibrations associated with combustion and knock results in the conclusion that neither the autoignition theory nor the detonation-wave theory is an adequate explanation of spark-ignition engine knock. A knock theory is proposed, combining the autoignition and detonation-wave theories, which introduces the idea that the detonation wave develops in autoignited or after-burning gases, and ascribes comparatively low-pitched heavy knocks to autoignition but high-pitched pinging knocks to detonation waves with the possibility of combinations of the two types of knocks" (p. 317).

Since the development of relationships between rod changes and temperature shifts, the temperature distribution of the B Pile has been improved as much as possible by shifting the rods. Certain unbalances have been found which can only be removed by improvement of the poison pattern. At present the maximum imperfection in the B Pile is 5% diagonal quadrupole unbalance. An estimate of the poison pattern needed to correct these imperfections is given herein. This poison pattern has been calculated as an example of application of the principles and is not intended as a recommendation.

Monthly progress report filled out by the Austin chapter of the the American Women's Voluntary Services discussing their news and activities.

Report discussing testing on two types of single cylinders to determine the effect of the relation of exhaust pressure to inlet-air pressure on knock-limited performance. Variables explored included exhaust pressure, fuel-air ratio, and engine speed. Three types of fuels were also used to explore the effect of exhaust pressure on fuel ratings.

Introduction. the conventional procedures of analysis for uranium and manganese can be employed in the analysis of alloys of these metals. The alloys are reacted with perchloric acid and hydrogen peroxide, fumed to remove any chloride ions, diluted to volume and aliquots analyzed by redoximetry.

The work described in this technical report was undertaken as part of a larger program dealing with a systematic investigation of changes in the physical prosperities of artificial graphite due to neutron bombardment. Very pronounced among those changes is the increase in the elastic modulus. Since there is a general relationship between the elastic modulus of a given substance and its specific heat, it was expected that corresponding changes will occur in the specific heat. In conclusion, the experiments determined that it appears that the low temperature specific heat measurements of strongly bombarded samples will be helpful for the understanding of the nature and the mechanism of the changes produced by neutron bombardment and annealing.

Annual report from the University of Texas Medical School Department of Obstetrics and Gynecology, discussing the department's curriculum, research, publications, and other relevant information for the academic year.

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