This technical progress letter details Hanford Engineer Works activities for the time period of July 7 through July 13, 1944.

Technical report. Areas covered are properties of uranium halides, properties of uranium nitrides, and hydride formation at high pressure.

The resonance absorption of a lump is described in terms of three components. Calculations of resonance absorption are carried out using the model for the resonance spectrum of uranium recently derived; calculations are also made with variations of this model which involve local fluctuations in level strengths. For metal and oxide lumps the agreement with observation is satisfactory. For dilute mixtures, whose resonance activation was measured by Mitchell, computed values fall 20% to 30% above measured ones.

Abstract. If a pile rod gets bowed within its cooling tube it becomes warmer on the side which approaches the tube wall, and thermal expansion tends to warp it in the same direction as the original displacement. This was discussed roughly in N-601, and it was there concluded that the mechanism was not important for an isolated short slug. In connection with current development of continuous jacket (cartridge) assemblies, it seems desirable to look at this question again. In this case it is possible that the effect may be of some concern.

The bomb reaction slag produced at the ElectroMetallurgical X metal plant is at present divided into rich C-1 slag and lean C-2 slag by merely screening through a 4 mesh wire screen, the "on 4 mesh" material becomes the C-1 slag and the "thru 4 mesh" material becomes the C-2 slag. In the experiments covered by this report it was found that the concentration of the lean C-2 slag could be facilitated by the use of a 20 mesh screen for the slang separation in place of the 4 mesh screen, as the 20 mesh screen removed troublesome, small, hard lumps which passed the 4 mesh screen. Furthermore, it was found that the additional small lumps removed by the 20 mesh screen were just as rich in X metal as the larger lumps which make up the bulk of C-1 slag.

From abstract: "Comparison of the activity produced by fast neutrons on lead with other activations corroborates the assignment of the 3.2 hr. activity as Pb209, and the assignment of the reaction as capture of fast neutrons. Two different measurements show that the neutrons captured have energies greater than 100 KEV. This average capture cross section for primary neutrons from 7.5 MEV deuterons on a thick target of beryllium is measured as 10[^]-27 ca[^]2."

Report discussing an investigation of 24 aromatic amines as antiknock additives in aircraft gasolines and their low-temperature solubility.