The temperature coefficient of eta has been measured with the thermal column of the Argonne pile using uranium foils of different isotopic ratios. The temperature change was effected by filtering neutrons through silver. The measured fractional change per degree centigrade is [formula].

Bi-Pb eutectic and pure Bi penetration of graphites of various densities under 300 degrees C and pressures up to 20 psi was found be of the order of magnitude of 1.0 g/cm(2) and was uniform throughout the graphite. Bi was absorbed less than the eutectic but the oxidation rate of Bi would be prohibitive. There was heavy nitriding in N atmospheres with the Bi and the eutectic.

Report presenting flight measurements of the pressures on the horizontal tail surfaces of a typical propeller-driven pursuit airplane during stalled pull-outs at high Mach number. Unit loads measured on the stabilizer at safe maneuvering limits were not only considerably in excess of the design unit loads, but also occurred in a direction opposite to the design loads. Revision of the tail-load design requirements and manner of specifying safe maneuverability limits to pilots appears necessary.

An analysis has been made of the drag losses in airplane flight of cross-flow plate and tubular intercoolers to determine the cooling-air weight flow and pressure drop that give a minimum drag loss for any given cooling effectiveness and, thus, a maximum power-plant net gain due to charge-air cooling. The drag losses considered in this analysis are those due to (1) the extra drag imposed on the airplane by the weight of the intercooler, its duct, and its supports and (2) the drag sustained by the cooling air in flowing through the intercooler and its duct. The investigation covers a range of conditions of altitude, airspeed, lift-drag ratio, supercharger-pressure ratio, and supercharger adiabatic efficiency. The optimum values of cooling air pressure drop and weight flow ratio are tabulated. Curves are presented to illustrate the results of the analysis.

The following report is the result of a reconnaissance of the black shales of the Eastern United States in the summer of 1944. The purpose of this reconnaissance was to determine the radioactivity of the shales, specifically for uranium and thorium.

Abstract: "For defects between interior and coating, or between successive layers of coating, a simple, fairly accurate formula is established. The temperature rise at the edge of the defect is briefly discussed."

Some methods for calculating the k requirements of various shaped piles are indicated, with particular reference to the shape of the tank in the homogeneous plant.