From introduction: "It is the purpose of this report to give two further methods of determining end point of pontentiometric titration, neither of which require the plotting of a graph."

From introduction: "At the request of WAPD, a study has been made of the effect of minor compositional variables on the corrosion behavior of uranium-molybdenum alloys in 650 F degassed water."

Report presenting simulator studies of a homing missile pursuing a constant-velocity nonmaneuvering target. The missile dynamics in pitch and roll, seeker method of deflection and control, and the missile-target geometry were simulated to determine whether the method of control and detection in conjunction with the missile dynamics were feasible.

Report presenting flight tests using a rocket-propelled 60 degree delta-wing body configuration, which included a NACA 0003-63 wing airfoil section. Drag at lift and stability data were obtained for a range of Mach numbers.

From Summary: "A method of computing span loads and the resulting rolling moments for sideslipping wings of arbitrary plan form in incompressible flow is derived. The method requires that the span load at zero sideslip be known for the wing under consideration. Because this information is available for a variety of wings, this requirement should not seriously restrict the application of the present method. The basic method derived herein requires a mechanical differentiation and integration to obtain the rolling moment for the general wing in sideslip."

Memorandum presenting an experimental investigation of the adaptation of a transonic slotted tunnel to supersonic operation by enclosing the slots with fairings. The adaptation allows the extension of peak Mach number of the tunnel to be made at a reasonable cost in both time and effort, provided simplicity and ease of installation are taken into consideration during the design of the cover fairings. The nozzle is found to be sensitive to phenomena that will cause thickening of the boundary layer in the slot cover fairing.

Report presenting an investigation of a model of the Kingfisher XAUM-2 flying torpedo to determine the pressure recoveries within the jet engine nacelle and to determine the effects of several changes in model configuration on the aerodynamic characteristics of the model. The effectiveness of elevons and tabs as control devices was also investigated.

Report presenting airspeed and altitude data for nonscheduled cargo operations of a Douglas DC-4 airplane between Seattle, Washington and Alaska during February and March of 1947 to determine the probability of reaching or exceeding given values of airspeed and Mach number. The total probability of exceeding a placard never-exceed speed of 266 mph depends primarily on exceeding the speed in descent. The probability was found to be about once in 100 hours of descent or once in 1000 hours of general flying time.

Memorandum presenting an analysis of selected experimental pressure-distribution data at transonic speeds for the purpose of deriving an empirical method which may be used for estimating the trailing-edge loads and bending moments at the design stage. The trailing-edge normal-force and bending-moment coefficients calculated by the derived method follow the general trend of the experimental data and appear to be a guide where specifically applicable chordwise pressure-distribution data at transonic speeds are not available.

Report presenting a method for the preparation and purification of the intermetallic molybdenum desilicide was developed and its properties were determined. Chemical properties were found to be highly inert, unattacked by boiling hydrochloric acid, sulfuric acid, or aqueous sodium hydroxide, slightly attacked by nitric acid, and dissolved by molten sodium hydroxide. Other mechanical properties of the material were also provided.

Report discussing testing in the low-turbulence tunnel to determine the effectiveness of several configurations of vortex generators in increasing maximum lift of a 6-percent-thick symmetrical circular-arc airfoil section. None of the configurations tested were found to greatly increase the lift. Some of the configurations tested included a single row of vortex generators, two rows of generators, larger vortex generators, and sweeping forward the front row of generators.

Report presenting a free-flight investigation of a rocket-powered control research model to determine the force and hinge-moment characteristics of a half-delta tip control on a delta wing. Results regarding the control hinge moments, control normal force, and total normal force are provided.

Report presenting an investigation of the planing characteristics of various combinations of a wheel and a hydro-ski. Models tested included at least two values of the following parameters: diameter of wheel, width of wheel, cross-section shape of wheel, fore-and-aft location of wheel, lateral location of wheel, gap between wheel and ski, rotation of wheel, and protrusion of wheel. Results regarding the general effect of a wheel, effect of wheel shape and size, effect of wheel-ski arrangement, and possible methods of reducing resistance are provided.

Report presenting tests in the 11-inch hypersonic tunnel at Mach number 6.86 to determine the effectiveness of an adjustable supersonic diffuser without boundary-layer control in reducing the pressure ratios across the system required to maintain supersonic flow. Testing indicated that the pressure ratio could be reduced to about one-third the pressure ratio required for starting.

Report presenting a flight investigation of a small, all-movable tail to determine whether it is an effective longitudinal control for a cruciform, delta-wing missile at a range of Mach numbers from 0.67 to 1.81. The stability, control, hinge-moment, and drag characteristics are provided.

An investigation of the performance characteristics of annular-diffuser designs applicable to turbojet afterburners. The best vortex-generator installations improved the diffuser static-pressure rise and downstream radial distributions without significantly altering the loss coefficients. Results regarding the axial inlet flow and whirling inlet flow are provided.

Equations are presented for the attenuation characteristics of single-chamber and multiple-chamber mufflers of both the expansion-chamber and resonator types, for tuned side-branch tubes, and for the combination of an expansion chamber with a resonator. Experimental curves of attenuation plotted against frequency are presented for 77 different mufflers with a reflection-free tailpipe termination. The experiments were made at room temperature without flow; the sound source was a loud-speaker. A method is given for including the tailpipe reflections in the calculations. Experimental attenuation curves are presented for four different muffler-tailpipe combinations, and the results are compared with the theory. The application of the theory to the design of engine-exhaust mufflers is discussed, and charts are included for the assistance of the designer.

Memorandum presenting an investigation of the dynamic stability of the Bell X-5 research airplane at 58.7 degrees sweepback and at altitudes of 40,000 feet and 25,000 feet over a Mach number range of 0.5 to 0.97. The results show that the longitudinal oscillatory motions are well damped over the entire Mach number range except for residual oscillations resulting primarily from engine gyroscopic coupling with the lateral oscillatory mode. The longitudinal and lateral frequency-response characteristics were obtained and some coupling effects were noted.

From introduction: This report summarizes a study of the composution and physical properties of a number of hydrocarbon diluents together with some generalizations regarding relations between [vapor pressure, density and viscosity] properties.

Abstract: "Fifteen in situ interval densities were calculated from the borehole gravity meter observations made in Test Well-B. The weighted average density for all the rocks sampled by the gravity meter is 1.83 gm/cc. The alluvium density ranges from 1.71 to 1.82 gm/cc and averages 1.76 gm/cc. The lake beds range from 1.91 to 1.93 gm/cc and average 1.92 gm/cc. The Rainier Mesa Member averages 1.83 gm/cc. The Tiva Canyon Member averages 1.74 gm/cc and the upper 110 feet of Topopah Spring Member has a density of 2.30 gm/cc."

This is a progress report on the carbonate process, compiled by the chemical development department of the Carbide and Carbon Chemicals Corporation's Y-12 plant, covering the month of September, 1949. In the previous month, the problem of immediate interest to the Monticello operation were listed. Projects that were left incomplete during that time were continued during this month, as well as a brief investigation of the process in which raw ore is leached with sodium carbonate, the sands and slime separated, the sands leached with acid, and the slimes roasted in a pellitized form.

Abstract: "An accurate calculation is given for the quantity which corresponds to the diffusion length in the theory of the pile. The procedure is to establish a relationship between the diffusion length and the change in thermal utilization from a pile with infinite sides to one with sides of a finite length. The calculation of this change in the thermal utilization is then carried through. Approximation to the answer and numerically exact calculations are given in the report. The results show that for radif very near the optimum values the exact diffusion length is slightly larger than the one obtained from the usual formula...However, over most of the range of radii the exact diffusion length is smaller than the approximate one."

A two and one-half year period of extreme caution where titanium and nitric acid are involved has passed since the occurrence of the last and most serious uncontrolled incident involving titanium and nitric acid. During this period controlled explosions involving titanium and nitric acid have been routinely reproduced, additional laboratory and pilot plant experience has been gained and successful industrial applications have been appraised. Based on laboratory data and the known industrial experiences, it is concluded that titanium can be safely employed in systems handling nitric acid that contains more than two (2) percent water. It is recommended that the titanium heat exchanger recently fabricated by the Technical Shops be installed in the Purex Plant plutonium concentrator when replacement of the stainless steel unit now in service becomes necessary.

New reactors presently in design or construction stages, as well as revised operating procedures for existing reactors, have shown an increasing emphasis on extending the exposure time of the reactor fuel elements. However, operating experience at Hanford, as at other installations, has demonstrated that as the amount of burn-up in uranium metal is increased an increase is also noted in operational difficulties resulting from the dimensional behavior of the fuel. During reactor irradiation uranium slugs or rods have been observed to change in length and diameter, to warp, and to develop surface roughening.