This report was written to replace the directions submitted on April 12, 1943 with improved directions for the preparation of chemical solution X(OC₂H₅)₅.

A report on using aluminum titanate as a ceramic materiel.

From introduction: "Studies were made of single crystals of thorium nitrate hydrate which we had available in this laboratory and from these we were able to determine the unit cell and find the thorium positions. These crystals contain on the order of six water molecules per thorium atom, but the exact composition is in some doubt."

Experimental study of effects of combustion roughness and controlled mechanical oscillations on diffuser operation was conducted on an 8-inch ram jet at Mach number 1.87. Within experimental accuracy, the optimum mean combustion-chamber static pressure occurred when the maximum instantaneous static pressure equalled the optimum steady-flow value and the corresponding decrement in optimum mean static pressure was equal to one-half the total amplitude of the pressure pulsations. A marked attenuation of amplitude of cold-buzz pressure fluctuations was effected over limited range of subcritical diffuser operation by means of properly tuned rotating disk located in combustion chamber.

From introduction: "In this report an attempt was made to summarize the results of recent research on the effective height of smoke stacks. In this summary attention is paid only to the case in which the density of the stack effluent is the same as that of the surrounding air."

Analytical methods for the presence of the refractory substances in sodium are described.

The following report studies the effect of flow rates and deposition pressure on the zirconium deposition in the zirconium pilot plant with the use of a Hilco oil purifier for the vacuum pumps that permitted studies to continue through the month.

Report presenting an investigation at transonic speeds to determine the control characteristics of a linked tab and flap. The control device consisted of an auxiliary lifting surface (tab) mounted on the end of a boom which was linked to a full-span flap. The tab was found to be capable of reducing the flap hinge moment to zero through the angle of attack and Mach number range tested.

The total neutron cross sections for normal uranium, U235, and Pu239 are reported as a continuous function of energy for neutron energies between 40 and 7500 Kev. Three additional measurements were made between 17 and 20 Mev. The data were obtained from a good geometry transmission experiment in which 1-in.-diameter cylindrical samples were interposed midway between a neutron source and a neutron counter spaced at about 20 in. separation. In general, the statistical errors were within +- 0.2 barn. Measurements on normal uranium were in agreement with those made at Wisconsin in 1950 (LA-1060). The total cross section curves are almost identical for the three materials and very similar to those of other heavy elements. This suggests that the total neutron cross section for other heavy elements can be predicted with some accuracy.

Report presenting wind-tunnel studies of the wake behind eight types of canard control surfaces of equal span mounted on a missile body at Mach number 1.93. The effect of simulated external rocket boosters on the pressure field was also determined for three control-surface plan forms. The investigation also included the effect of end plates attached to the tips of one of the controls surfaces.

Report presenting testing of a 14-inch supersonic mixed-flow rotor of high specific mass flow and an inlet radius ratio of 0.52, which was designed for impulse operation and uniform work output and tested in Freon-12. Results regarding the overall rotor performance, casing friction, entrance flow, distribution of static pressure on the casing, and exit flow are provided.

Memorandum presenting the results of an investigation of control-surface buzz and flutter on four rocket-powered models with a 4-percent-thick unswept wing and 6, 9 and 12-percent-thick 35 degree swept wings with free-floating and statistically mass-balanced control surfaces. The results showed that all of the control surfaces buzzed. The buzz is related to the presence of a shock wave near the control surface for subsonic speeds.

Report presenting a flight investigation of the variation of the intensity of buffeting with lift and Mach number using a Douglas D-558-II research airplane over a range of Mach numbers and altitudes. Buffeting was encountered during flight at all Mach numbers attained and during level flight at Mach numbers above 0.9. Results regarding the relationship between lift, angle of attack, and buffeting, buffet frequencies, and intensity of buffeting are provided.

Report presenting a wind-tunnel investigation conducted a range of Mach numbers of a 45 degree sweptback wing with varying camber along the span. Two other wings, one with no camber and one with uniform camber, were also tested. Results regarding the wing characteristics and control characteristics are provided.

This method essentially consists of analyzing x-ray filtration data in terms of Laplace transforms and obtaining the spectral energy distribution in terms of a sum of the corresponding inverse Laplace transforms. Some of the functions which are especially suited for this application are given and a graphical method of analyzing filtration data in terms of these functions is described. Examples of the practical application of this method to several low energy x-ray machines are included with a discussion of the advantages, disadvantages, and probable uncertainties which are involved.

A limited exploratory investigation of the rate of coking of four JP-4 fuels in electrically heated metal tubes was conducted in order to provide design information for fuel prevaporizers for turbojet-engine combustors. The fuels tested included two production and two minimum-quality JP-4 type fuels. The heating tube was operated at fuel pressures of approximately 500, 400, and 50 pounds per square inch. The operating fuel temperature was varied between approximately 600 degrees and 1200 degrees F.

Memorandum presenting a high subsonic Mach number turbine with high suction-surface diffusion investigated experimentally. The subject turbine was designed for a high weight flow per unit frontal area, a high specific work output, and a relative critical velocity ratio of 0.82 at the rotor hub input.

Report presenting an experimental investigation of a high subsonic Mach number turbine with high suction-surface diffusion. The subject turbine was designed for a high weight flow per unit frontal area, a high specific work output, and a relative critical velocity ratio of 0.82 at the rotor hub inlet.

By use of small magnetic probes inserted into the discharge, the magnetic field distributions in the interior of a high-power pinched discharge have been measured as a function of time. From these data the current distributions can be deduced. By applying a static pressure calculation, in the cases when the radical pinch accelerations are small, the plasma pressure nkT in the pinch has been determined, with superimposed axial magnetic fields, and for stable and unstable configurations.

Report presenting summaries of full-scale engine tests of pentaborane, pentaborane-JP-4 fuel mixtures, and trimethylborate-methyl-alcohol-azeotrope fuels. Tests were conducted at an altitude of 50,000 feet and Mach number of 0.8. Results regarding the fuel effects on overall performance, effects on component performance, effect of turbine-outlet temperature on engine performance, and miscellaneous observations are provided.

This report summarizes the full-scale engine tests of pentaborane, pentaborane - JP-4 fuel mixtures, and trimethylborate azeotrope fuel. The tests were conducted in a full-scale turbojet engine at a simulated altitude of 50,000 feet and Mach number of 0.08. Engine speeds were 90 to 100 percent of rated speed. Pentaborane reduced the the specific fuel consumption to two-thirds that of JP-4 fuel. However, because boron oxide collected in the engine, the performance deteriorated with continued operation of pentaborane in each of the short-duration tests reported.

Supersonic performance of variable two-dimensional inlets designed for engine-inlet matching.

"This document includes papers covering technical problems involved in the design, construction and operation of the APPR-1" (p. 4).

Report presenting an experimental investigation to determine the effects of vertical location of an unswept wing and horizontal tail on the aerodynamic characteristics in pitch of a wing-body-tail combination. The wings had an aspect ratio of 3.09, a taper ratio of 0.39, the quarter-chord line swept back 11.5 degrees, and biconvex sections.