A method using photographic emulsions for the study of neutron distributions is described. The construction of a simple machine for producing experimental critical assemblies in which the method has been used is reported. Sources of error are discussed. Curves of the perturbations when small spheres of various materials are placed in the center of the assembly are shown.

The purpose of this report is to present a basis for the application of slug corrosion rate data to corrosion limitations on pile power levels.

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Price Daniel, regarding a legal question submitted for clarification: Authority of the Commissioners' Court to lease or sell a hospital building to a non-profit private organization for operation as an old folks' home.

Report presenting an investigation of the aerodynamic loading characteristics of a wing-fuselage combination in the slotted test section of the transonic tunnel. The test was part of a systematic investigation of the effects of varying the amount of sweepback on wings in order to determine their suitability for transonic flight. Results regarding span load characteristics, normal-force characteristics, wing-tip angle of twist, spanwise distribution of section pitching-moment coefficient, pitching-moment characteristics, and fuselage characteristics in presence of wing are provided.

The chain reacting conditions for plutonium nitrate in water solution have been examined experimentally for a variety of sizes of spheres and cylinders. The effects on the critical mass of the displacement of hydrogen and the addition of poisons to the fuel were measured in water tamped and bare reactors. In this report the data obtained in the investigation is presented graphically and in tables. Some preliminary analysis has been made yielding the results: (i) the absorption cross-section of Pu{sup 240} is 925 {plus_minus} 200 barns and (ii) the minimum critical mass of Pu{sup 239} in water is 510 grams at concentration of about 33 grams per liter.

Memorandum presenting results obtained from time-history records of normal accelerations, airspeed, and altitude. Additional data have been obtained from the operations of two types of commercial transport airplanes together with data on two other types of transport airplanes.

The Process Unit has requested the Present Canning group to evaluate two alkaline cleaners, Pennsalt A-10 and Turco ``Aviation`` Cleaner, as possible substitutes for the present trichloroethylene vapor degreaser and Duponol wash. Disadvantages of the present cleaning procedure are: ineffectiveness; expense; toxicity of trichloroethylene. The alkaline cleaners Pennsalt A-10 and Turco ``Activation`` Cleaner were tested and compared with an alkaline cleaner made from Na{sub 2}CO{sub 3} and Na{sub 3}PO{sub 4} and with the present cleaning method. With available equipment Pennsalt A-10 and Turco ``Aviation`` Cleaner did not remove grease and dirt as well as the present cleaning method. A solution of Na{sub 2}PO{sub 4} and Na{sub 2}CO{sub 3} was the best degreaser tested although it did etch the surface of the cap. This document provides a discussion of the procedure utilized and the results.

Report presenting the application of an aerodynamically pulsed horizontal tail to determine experimentally the longitudinal aerodynamic characteristics of a rocket-powered model in free flight. Results regarding time history, lift and drag, and tail effectiveness and downwash are provided.

This is a progress report of the production reactors on the Hanford Reservation for the month of April 1952. This report takes each division (e.g., manufacturing, medical, accounting, occupational safety, security, reactor operations, etc.) of the site and summarizes its accomplishments and employee relations for that month.

None

Abstract: The yields of U²³⁷ and a fission product were measured as a function of maximum betatron energy, The ratio of the number of fissions divided by the number of U²³⁷ atoms increases with increasing maximum betatron energy. This is consistent with the picture that the higher-energy gammas leave the U²³⁷ atoms with enough excitation energy (above photofission and photoneutron thresholds) to also decay by fission or neutron emission. This secondary process increases the number of fissions and decreases the U²³⁷ yield, this increasing the above ratio.

Report presenting an investigation at Mach number 1.6 and a range of Reynolds number of the skin-friction drag and boundary-layer transition of a body of revolution. The body had a parabolic-arc profile, a blunt base, and a fineness ratio of 12.2 (NACA RM-10). Results regarding the effect of surface condition, drag breakdown, and results of boundary-layer surveys are provided.

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Price Daniel, regarding a legal question submitted for clarification: Method to determine the amount assigned to be raised by a county-line school district toward financing its foundation school program.

"A pneumatic probe based on continuity of mass flow through two restrictions separated by a cooling chamber was constructed to measure gas temperature at and beyond the limit of thermocouples. This probe consisted of a subsonic flat-plate orifice for the first restriction and a sonic-flow converging-diverging nozzle for the second restriction. The effect of variation in gas constants on the calibration is examined for common engine-exhaust gases" (p. 1).

This report presents "Results of a critical literature review on pressure drop due to isothermal turbulent flow in noncircular geometries" (introduction).

Memorandum presenting an investigation of a 2:1 area ratio conical diffuser of length equal to the inlet diameter with separate variation of several basic parameters for simple nontwisted counterrotating rectangular vortex generators over a considerable range of inlet-boundary-layer thickness. The maximum values of static-pressure rise were determined for angle of attack, spacing, aspect ratio, and span-to-inlet boundary-layer thickness. Results for the diffuser with no vortex generators, effects of selectable vortex-generator variables, effect of inlet-boundary-layer displacement thickness, and use of the maximum indicated vortex-generator design values are provided.

In solving the two-group, two medium equations for neutron diffusion in a finite one-dimensional multiplying system, the equations in each medium can be solved, and the boundary conditions used to determine the coefficients. This direct attack involves eight simultaneous linear equations. The opportunities for error are numerous, and, frequently, a great deal of accuracy is lost by subtractions; hence, it is felt that an alternative method of solution, in which numerical errors would be less likely to occur, would be desirable.

Memorandum presenting flutter tests of untapered, low-aspect-ratio, sweptback-wing models and of triangular-wing models of solid magnesium, aluminum, and steel construction in an intermittent supersonic wind tunnel at Mach number 1.3. Flutter data are presented for 31 sweptback wing models and 24 triangular-wing models. The flutter boundaries are indicated on plots of streamwise thickness ratio and aspect ratio.

Report presenting a low-speed investigation in the stability tunnel to determine the effects of tail height, length, and aspect ratio on the static longitudinal stability and control characteristics of a 60 degree triangular-wing model with twin triangular all-movable tails located near the wing tips.

None

"Preliminary results of one phase of a control-motion study program are presented in the form of plots of load factor.and angular acceleration against indicated airspeed and of time histories of several measured quantities. The results were obtained from 197 maneuvers performed by an F-86A jet-fighter airplane during normal squadron operational training. Most of the tactical maneuvers of which the F-86A is capable were performed at pressure altitudes ranging from 0 to 32,000 feet and at indicated airspeeds ranging from 95 to 650 miles per hour" (p. 1).

From abstract: High velocity disturbances are observed to propagate along the walls of a high explosive operated shock tube in advance of the plane shock. Experiments are presented which determine the dependence of the geometry, energy, and velocity of the disturbance on such variables as the gas contained in the shock tube, the shock strength, and the roughness and composition of the supporting boundary. A model is constructed to explain the flow within the disturbance. Arguments are presented which show the disturbance to result from radiation originating in the luminous plane shock...The purpose of this paper is to present the results of initial investigations made in an effort to describe the phenomenon of strong shocks developed in a shock tube by the detonation of high explosive charge.

During the preliminary operaton of a volatilization apparatus it became apparent that a large stopcock in the high vacuum side of the oil diffusion pump was quite unsatisfactory. Since it was necessary to mount the stopcock in a relatively inaccessible location, the difficulty of turning the plug and the consequent necessity of regreasing the valve approximately every week were real problems. Also, it became apparent that an increased pumping speed through the valve would be required. Since a larger stopcock was out of the question, a type of valve reported by Stern was modified in design and was bulit into the apparatus.

None