Abstract: "The protection of thorium in hot water was studied. Copper electrocladding on thorium offers promising protection against hot water. The corrosion of thorium in 95 C water was reduced appreciably by a thorium phosphate film. The results of this abbreviated investigation offer a basis for the development of a method of protecting thorium at elevated temperatures in corrosive media."

This report has two parts to it discussing mineralogical examination of pitchblende concentrates and nitric acid digest residues. Part I gives the results of a cursory examination with the petrographic microscope of samples of pitchblende concentrates and residues to see if there is a relationship between the mineral composition of the samples and the filterability of the residue. Part II gives a revaluation of the data in Report BMI-241 on the mineral composition of two residues from the nitric acid digestion of pitchblende concentrates at the Rallinckrodt Chemical Works.

From abstract: "The composition of vapors from aqueous nitric acid solutions boiling at 200 mm mercury total pressure is established for solutions containing between - and 67.5 w/o nitric acid. The volatility characteristics of low concentrations of chloride in the same concentration range of nitric acid have been measured in solutions boiling at 200 mm mercury. The effects of chloride concentration and pressure of boiling are evaluated. A spectrophotometric method of the determination of chloride in nitric acid solutions is described."

Report discussing experiments on the interaction of neutron-absorber materials and metal matrix materials used in the fabrication of control rods, such as "boron, cadmium, and some of the rare-earth elements such as gadolinium and europium...In order to evaluate the reactions that might occur during fabrication and use, experiments were carried out in which combinations of the various control materials were heated in intimate contact with the several matrices at elevated temperatures."

Technical report covering the technology of hot-pressed beryllium production and its rapid advancement toward the end of 1949. Part I is devoted to corrosion studies made on hot-pressed and vacuum cast extruded metal which was considered representative of production. Part II is concerned with the results of tests made on special cast and hot-pressed beryllium which contained added impurities. [From Introduction]

Technical report outlining the investigation of corrosion on MTR type fuel elements for the Shielding Reactor in filtered water. Report includes two basic types of protection: element pretreatment by either anodizing or alodizing, and solution control using nitric acid to maintain a pH of 5.5 to 6.5 or the addition of 60 ppm sodium chromate as an inhibitor. [From Abstract]

The first part of this quarterly progress report details reactor theory and design, discussing the aircraft reactor experiment, experimental reactor engineering, reactor physics, and critical experiments. The second part of this report is not included. The third part of this quarterly progress report details materials research, discussing corrosion research, physical properties and heat-transfer research, metallurgy and ceramics, chemistry of high-temperature liquids, and radiation damage. The fourth part of this quarterly progress report details alternate systems, discussing a supercritical water reactor, circulating-moderator-coolant reactors. The fifth part of this quarterly progress report includes appendixes.

Thesis discussing "a technique for determining the generation times of individual yeast cells...the effect of x-radiation on the generation times of individual cells and their progeny..." and "attempts to synchronize cell division in a population of cells."

Abstract: "Formulas are derived for the trajectory of a charged particle in a magnetic field which is a linear function of time. Graphs of certain functions are presented, by means of which a trajectory with given initial position and velocity may be plotted."

From introduction: "This is the first of three articles dealing with the influence of fluorine substitution in the ligand on the properties of metal chelate compounds. Although the primary purpose of this project was to study the influence of fluorine substitution on the properties -- particularly light absorption -- of uranyl compounds, copper chelates were chosen for preliminary study as model substances, because they are easily prepared."

From Abstract: "This paper deals with the vacuum design considerations of large systems involving the application of 8-inch through 32-inch mercury diffusion pumps. The selection, rating, and optimization of pumps are discussed along with the closely allied problem of baffling the pumps. The materials of construction and methods of fabrication to avoid subsequent system contamination are dealt with in detail. System interlocking and its associated instrumentation are illustrated by referral to the operation of a large particle-accelerator vacuum system."

From abstract: "The motion of a charged particle in a region of crossed electric and magnetic fields is discussed... Possible applications of such a system to various problems in nuclear research are suggested and it is shown to be possible in principle to measure the kinetic energy, mass, and ionic charge of various nuclear-reaction products and to separate various short-lived products for rapid examination. Two different devices are proposed. The application of the technique to investigation of the fission process is specifically discussed."

Abstract: "The cross section for the Be-9(n, t')Li-7*-->Li-7 + Y(0.477 Mev) reaction has been measured in the vicinity of 14 Mev by detecting the gamma-rays at scattering angles from 30 to 150 degrees. A time-of-flight technique was used to distinguish the gamma-rays from the high neutron background. The cross section drops from 20 mb at 13.6 Mev to 10 mb at 14.1 Mev and then rises to 30 mb at 14.7 Mev."

Report presenting a theoretical method for calculating heat transfer in the laminar boundary layer on yawed infinite cylinders in compressible flow. The method can be applied to a cylinder of arbitrary cross section and arbitrary chordwise wall-temperature distribution. The variation in local heat transfer around the surface of the cylinder was found to have little functional dependence on yaw angle or wall temperature.

Report presenting testing of two 2024-T3 aluminum-alloy multiweb wing structures (MW-2 and MW-3), similar to airplane or missile wings, at a Mach number of 2 under simulated supersonic flight conditions. Results regarding experimentally determined test conditions, model temperatures, strain-gage results, and model failures are provided. The report indicates that much of the stress data does not agree with expected results, but there is too much uncertainty regarding the reduction of strain data that no conclusions can be made concerning the results.

Report presenting the gross weight and uranium investment of nuclear-powered, direct-air, shieldless, ram-jet missiles for a range of altitudes and Mach numbers. Results regarding the effect of reactor operating conditions and flight conditions on ramjet performance and effect of assumptions on ramjet performance are provided.

"Some of the considerations involved in the design of aircraft fuel tanks for liquid hydrogen are discussed herein. Several of the physical properties of metals and thermal insulators in the temperature range from ambient to liquid-hydrogen temperatures are assembled. Calculations based on these properties indicate that it is possible to build a large-size liquid-hydrogen fuel tank which (1) will weigh less then 15 percent of the fuel weight, (2) will have a hydrogen vaporization rate less than 30 percent of the cruise fuel-flow rate, and (3) can be held in a stand-by condition and readied for flight in a short time" (p. 1).

Memorandum presenting an investigation of an experimental tubular combustor that provides for prevaporizing and premixing of the fuel with a part of the air before its introduction into the combustion zone. Combustion efficiency and total-pressure loss data are presented for three configurations selected from a total of 43 different modifications investigated. Results regarding the combustor development, comparison of liquid and gaseous fuel, combustor total-pressure losses, combustor-outlet temperature distribution, and evaluation of experimental prevaporizing combustors are provided.

Report presenting theoretical performance characteristics and estimates of effective specific impulse and weight for rocket engines serving a main and booster power plants for missiles. The fuels used included ammonia-fluorine and JP4-oxygen propellants. At extremely high altitudes, the specific impulse depends primarily on the expansion ratio.

Report discussing the low-speed stability and control characteristics of a modified model of the MX-1554A with a triangular wing and triangular stabilizing surfaces, which are designed to give more satisfactory stability and control than previous versions. Other modifications included an increase in slotted-flap span, redesigned tip aileron, fuselage tail cone, and speed brakes. Results provided include the effect of flow-control devices, tank and pylon location, a ground board, rotary stability derivatives, and a single support strut on the stability, control, and aerodynamic characteristics.

Memorandum presenting the application of the nuclear-reactor simulator to an investigation of the validity of the customary assumption of uniform distributions of fuel burnup and fission-product poisoning in a reactor core. The two-group calculation results show the effects of the approximation on the reactivity, power distribution, and xenon-135 distribution for a specific power reactor in which the initial power density varied by a factor of approximately 4 over the core volume.

Report discussing an investigation to determine the low-speed aerodynamic characteristics of a North American FJ-3 airplane with a segmented spoiler-slot-deflector lateral control system installed ahead of convention ailerons and operated as individual units and as combined segments. The longitudinal characteristics of the plane, the spoiler-slot-deflector effectiveness, and spoiler-deflector hinge-moment data are all described.

Memorandum presenting a theoretical investigation to determine the reasons for poor airplane response to longitudinal control. Some effects of airplane configuration on the response, primarily for short time periods, were also determined. Results regarding a comparison of three airplanes, the effect of changes on airplane B, and the effect of changes on airplane C are provided.

"An investigation was conducted in the NACA Lewis altitude wind tunnel to improve the altitude performance and operational characteristics of an afterburner primarily by modifying the diffuser-exit velocity profile by changes in diffuser design and by changing the fuel distribution and the flame holder. Twenty configurations, consisting of combinations of six diffuser geometries, six flame-holder types, and twelve fuel systems, were investigated. Data were obtained over a range of afterburner fuel-air ratios at diffuser-inlet total pressures from 2750 to 620 pounds per square foot" (p. 1).