Simple expression are derived for the time dependence of slowing down of neutrons in a simple media. In Section I, a method suggested by age theory is used, while in section II, a two parameter scattering function is employed. Results are compared with exact calculations.

"Wake development behind circular cylinders at Reynolds numbers from 40 to 10,000 was investigated in a low-speed wind tunnel. Standard hot-wire techniques were used to study the velocity fluctuations. The Reynolds number range of periodic vortex shedding is divided into two distinct subranges" (p. 1).

At the time the first UO{sub 3} from so-called ``full-level`` Redox runs was shipped from 224U, the % U{sub 235} as determined in 222-S appeared high when compared with theoretical values from the burn-out curve. Close agreement between the 222-S results and % U{sub 235} determined by K-25 on lots 007, 008, and 009, however, indicated that a considerable heel of cold uranium in Redox had been blended with the first ``full level`` material. This explanation has been verified by data collected over the past weeks and provided this report. It has also been verified by the % U{sub 235} found in lots later than 010* (after most of cold uranium flushed out of Redox) which ranged from 0.66% to 0.64%.

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From Introduction: "The intermediate subsonic speed range is considered and the liquid-metal turbine-propeller cycle discussed in this report. In this report, compressor pressure ratio, heat-exchanger air-inlet Mach number, and turbine-inlet temperature were optimized for maximum engine net thrust per engine-plus-heat exchanger weight (minimum airplane gross weight) for a range of heat-exchanger effective wall temperature."

From Introduction: "The intermediate subsonic speed range is considered and the liquid-metal turbine-propeller cycle discussed in this report. In this report, compressor pressure ratio, heat-exchanger air-inlet Mach number, and turbine-inlet temperature were optimized for maximum engine net thrust per engine-plus-heat-exchanger weight (minimum airplane gross weight) for a range of heat-exchanger effective wall temperature."

Map of the area surrounding the census-designated place of Beclabito, San Juan County, New Mexico showing mine locations and mineralized rock exposures by geologic period, along with the location of triangulation stations with their elevation.

Preliminary recommendations are presented for drilling the area on a 1,000-foot grid to provide final elevation of the East Carrizo mining district.

Report presents the results of an investigation conducted to determine the effectiveness of liquid-cooling films on the inner surfaces of tubes containing flowing hot air. Experiments were made in 2- and 4-inch-diameter straight metal tubes with air flows at temperatures from 600 degrees to 2000 degrees F. and diameter Reynolds numbers from 2.2 to 14 x 10(5). The film coolant, water, was injected around the circumference at a single axial position on the tubes at flow rates from 0.02 to .24 pound per second per foot of tube circumference (0.8 to 12 percent of the air flow). Liquid-coolant films were established and maintained around and along the tube wall in concurrent flow with the hot air. The results indicated that, in order to film cool a given surface area with as little coolant flow as possible, it may be necessary to limit the flow of coolant introduced at a single axial position and to introduce it at several axial positions. The flow rate of inert coolant required to maintain liquid-film cooling over a given area of tube surface can be estimated when the gas-flow conditions are known by means of a generalized plot of the film-cooling data.

The question of maximum permissible levels of fission products or corrosion products in the pile effluent water which you raised is not a simple problem that can be completely answered by a list of maximum permissible levels. This water is a complex mixture of various isotopes each of which contributes to the total hazard according to the amount present, its particular metabolic features, and its mode of radioactive decay. Unfortunately, also, application of maximum permissible limits determined for consumption by humans may give only a part of the picture since it is necessary to consider also the effect on the ecology of the Columbia River and the ultimate effect on the aquatic life. With these considerations, we can make estimates of some limits which may be applied in design of new systems with, however, the reservation that practical application may depend on the mixture of isotopes actually encountered in operation. This document provides a discussion of maximum permissible levels of radioactive effluents and corrosion products in the reactor cooling water. 5 tabs.

Map showing uncontrolled structure contours of the Beclabito Dome Area, Shiprock District, Arizona-New Mexico. The Salt Wash-Bluff contact was spotted on aerial photographs as a basis for the construction of the uncontrolled structure contour map

Report presenting preliminary results of one phase of a control-motion study program using data obtained from 276 maneuvers performed using a McDonnell F2H-2 jet fighter airplane during normal squadron operational training. Results regarding classification of maneuvers, airspeed, load factors, sideslip angle, and maximum pitching-, rolling-, and yawing-angular-acceleration variations with indicated airspeed are provided.

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.

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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.

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"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).

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.

"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 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.