Memorandum presenting the results of wind-tunnel oscillation tests to measure the rotary derivatives of a research airplane configuration at supersonic speeds. Measurements were made of the damping in yaw, pitch, and roll, the static longitudinal and directional stability derivatives, the effective-dihedral derivative, the rolling moment due to yawing, and the yawing moment due to rolling. The configuration was found to be statistically stable throughout the Mach number range, although its stability was becoming marginal at high angles of attack at Mach number 3.5.

Wind-tunnel tests of a full-scale model of the Republic XF-91 airplane were conducted to determine the distribution of pressure over the external wing fuel tank installation and over the vee tail and ventral fin. The data were obtained for a range of angles of attack and sideslip and elerudder deflection angles; the presentation is in tabular form.

Pressures were simultaneously measured in the variable-density tunnel at 54 orifices distributed over the midspan section of 5 by 30 inch rectangular model of the NACA 4412 airfoil at 17 angles of attack ranging from -20 degrees to 30 degrees at a Reynolds number of approximately 3,000,000. Accurate data were thus obtained for studying the deviations of the results of potential-flow theory from measured results. The results of the analysis and a discussion of the experimental technique are presented.

"Working charts are given for the convenient selection of aluminum alloy propellers of a standard form, to operate in connection with six different engine-fuselage combinations. The charts have been prepared from full-scale test data obtained in the 20-foot propeller research tunnel of the National Advisory Committee for Aeronautics. An example is also given showing the use of the charts" (p. 3).

Report presenting an analytical study of four combinations of subsonic and supersonic flow in the rotor- and stator-blade passages of axial-flow compressors.

Reciprocal labelling in double-labelling experiments with H3- and C14- thymidine showed that when H3- thymidine (1μc/ml for 0.5 hr) was given first in the labelling sequence followed by a 4 hr interval before the C14- thymidine treatment, that passage of cells into and out of DNA synthesis was normal. When C14 was first in the sequence, the rate at which cells entered DNA synthesis was decreased. This was attributed to a radiation effect produced by the β-rays from the C14. The rate at which cells entered DNA synthesis was studied after 0.1, 1 and 10 rads of x-rays. A dose of 1 and 10 rads decidedly depressed the rate. Treatment of roots with 2, 20, and 200 μc/ml of tritiated water for 0.5 hr showed that the 2 higher concentrations produced an effect similar to the x-rays. This indicated that somewhere between 1 and 8 disintegrations per cell per 0.5 hr will produce a decrease in the rate at which cells enter DNA synthesis. In both the x-ray and H32O experiments the depression of the rate that cells entered DNA synthesis seemed to reach saturation at the higher doses.

An accurate determination of the parameters of the resonance excited by the interaction of the 132 eV neutrons with the Co 59 target nucleus has been made, using the fast choppers at Brookhaven National Laboratory in the United States and Chalk River Laboratory in Canada. Neutron transmission through thick and thin samples resulted in the following parameters: [parameters not transcribed]. In addition, measurements of the resonance capture γ-ray intensity gave the value for the radiation width Γγ= 0.40 ± 0.04 eV, based on the known thermal capture cross section of cobalt of 37.5 barns. The reduced and total resonance capture integrals are calculated from the above parameters to be 50.5 ± 5.5 and 67.0 ± 5.5 barns, respectively. The above results are compared with previously determined resonance parameters and also with direct measurements of the total resonance capture integral.

The probabilities for nine electronic transitions among the low lying excited states in the C2 molecule are calculated by the dipole moment operator method and are given in the form of oscillator strength (or f values).

Several compatibility test of various materials in contact in sodium under 500 psi pressure were conducted for 716 hr at 1500 F. Of the diffusion couples studies, the Inconel-beryllium system showed the largest amount al alloying. The reaction between molybdenum and beryllium resulted in the formation of two compounds, both of which were severely cracked in several areas. The molybdenum-INOR #8, and the INOR #8p type 316 stainless steel interfaces showed little if any alloying.