Report documenting the progress of the Army Gas-Cooled Reactor Systems Program to develop a mobile nuclear power plant for military field operation.

Investigations on the relative biological effectiveness (RBE) of densely ionizing radiations (with high LET, rate of linear energy transfer) are of importance in both fundamental and applied radiobiology. In the latter, they serve as a basis in setting permissible exposure levels for types of radiation about which little long range experience is available. Some of the best RBE studies have been done on chromosomal aberrations. The difficulty is determining RBE on the basis of chromosomal exchanges or 2-break aberrations is that the dose-response curves differ for radiations of different LET and dose rate. The dose-squared term tends to predominate with radiations of low LET (such as γ rays and most X rays) and high doses or dose rates; the linear term dominates with high LET tracks in general and at low doses or dose rates. The shape of the curves is thought to reflect the existence of two classes of mechanisms by which chromosome exchanges are produced; exchanges caused by the passage of a single ionizing particle account for the linear component of the dose-response curve, exchanges due to the interaction of effects of two independent ionizing particles are responsible for the dose-squared component. This model has been amply confirmed …

If one injects into an animal H3-thymidine, 50% of it is incorporated into deoxyribonucleic acid (DNA), within approximately 30 to 45 minutes, while the rest is catabolized. A storage of H3-thymidine for later incorporation into DNA does not occur, on the basis of available evidence. Once incorporated, the label remains bound to DNA until cell death and no unequivocal evidence has as yet been presented to indicate metabolic renewal or intracellular turnover of the DNA molecule. The loss of labeled DNA from the bone marrow is therefore directly influenced by the rate of proliferation of the various cell types with release of mature cells into the peripheral blood.

In brief, these facilities consist of a 250 KvP X-ray generator; two areas of a research reactor, one a well thermalized unit of moderate capacity and a larger area with a mixed thermal and fast neutron distribution, all of which are used for brief, acute exposure. A 10 acre field, currently with almost 4000 curies of cobalt 60, serves to irradiate entire plants for either short or long periods of time. Recently, the flux density of the thermal column was increased by a factor of 5 over the original density. This was accomplished by lowering the thermal column 12 inches deeper into the reactor shield. Fast neutrons at this higher flux density are also available to the cooperator. An additional facility available to the program is the array of kilocurie gamma sources in the Nuclear Engineering Department of Brookhaven National Laboratory.

Introduction. As has been shown by Post, the total power required to produce a strong, steady-state magnetic field is strongly dependent upon the temperature at which the electrical conductor of the magnet operates. The power required for operation at very low temperature can, in some cases, be much less than that required for ambient temperature operation. The power required for low temperature operation depends on many system characteristics which include the metal chosen for the electrical conductor, the purity of this metal, and efficiency of the refrigeration equipment. This paper shows the relative power requirement, as a function of temperature, of a magnet with a particular shape and with a field strength of 100,000 gauss. Data is shown for three electrical conductors: copper, aluminum, and sodium.

Memorandum presenting the effect of free-stream Reynolds number, engine installation, and model scale on inlet stability limits and on the amplitude and frequency of buzz. The data were taken at a free-stream Mach number of 2.0 and angles of attack from 0 to 6 degrees. Results regarding free-stream Reynolds number effect, model scale, and effect of engine on stability are provided.

Report presenting the effect of free-stream Reynolds number, engine installation, and model scale on inlet stability limits and on the amplitude and frequency of buzz. The data was obtained at mach number 2.0 and a range of angles of attack. Results regarding the free-stream Reynolds number effect, model scale, and effect of engine on stability are provided.

Report presenting an investigation of a two-stage turbine with a downstream stator to determine the interstage flow conditions of the turbine. Results regarding stage efficiency and work output, first-stage performance, second-stage performance, and downstream-stator performance are provided.

Memorandum presenting an investigation of the thermal stability of a commercial grade of propyl pentaborane at temperatures of 147 and 190 degrees Celsius. The products of decomposition are hydrogen, hydrocarbons, and a solid nonvolatile yellow boron hydride.

Memorandum presenting an investigation of the thermal stability of a commercial grade of propyl pentaborane (HEF-2) at temperatures of 147 and 190 degrees Celsius. The products of decomposition are hydrogen, hydrocarbons, and a solid nonvolatile yellow boron hydride. An equation is provided that can be used to calculate the approximate time required to decompose 20 percent of propyl pentaborane at other temperatures.

"A study was made of the effects of temperature, impurities in the hydrogen chloride, flow rates, and niobium content on both the reaction rates and insoluble uranium losses in the Zircex Process is presented."

An analysis has been made to determine the effect of chord size on the weight and cooling characteristics of shell-supported, air-cooled gas-turbine blades. In uncooled turbines with solid blades, the general practice has been to design turbines with high aspect ratio (small blade chord) to achieve substantial turbine weight reduction. With air-cooled blades, this study shows that turbine blade weight is affected to a much smaller degree by the size of the blade chord.

From introduction: "This report gives the results of a 1000-hour corrosion test of SAE 1010, low carbon steel, in synthetic Redox waste solutions...The present test was designed to obtain corrosion rates for waste solution temperatures of 180 F, 200 F, and 220 F in solutions neutralized to pH values of 11, 12, and 13.

Memorandum presenting tensile fatigue tests run on seven turbine-blade alloys at a temperature of 1500 degrees Fahrenheit and a mean stress of 22,000 pounds per square inch with superimposed alternating stresses of 0, 5000, 10,000, and 15,000 pounds per square inch. The same three types of fracture occurring in turbine blades - stress-rupture, stress-rupture followed by fatigue, and fatigue - were obtained in the specimens. Results regarding the effect of alternating stress on mechanism of failure, specimen life, reduction of area of fractured specimens, and effect of specimen shape on life are provided.

Report presenting an investigation of the radiative processes involved in combustion to determine the present role of radiant energy transfer in combustors. The equivalent gray-body emissivity of a hydrocarbon fuel may be increased by use of liquid or solid, soluble or nonsoluble, additives. Results regarding the experimental apparatus and methods, emission characteristics of luminous and nonluminous flames, absorptivity of fuels and of solutions of possible additives, and absorption by slurries are provided.

This report examines the failure of two 18-8 grade stainless steel gate valves used in sulfamic acid and determines the cause of the failures through a series of tests.

Report presenting an experimental investigation conducted a Mach number of 3.85 to determine the diffuser characteristics of a series of conventional axially symmetric nose inlets on a ramjet in a supersonic wind tunnel. Performance evaluations of single-cone, double-cone, and isentropic diffusers were made in terms of total pressure recovery and mass flow for a range of angles of attack. Results regarding performance of 1-cone inlets, performance of 2-cone inlets, and performance of isentropic inlets are provided.

Report presenting an experimental investigation at a Mach number of 3.85 in the supersonic wind tunnel to study the flow patterns at the throat of a two-dimensional single-shock diffuser and to evaluate qualitatively several schemes for improving the turning conditions. Schileren observations were made for supercritical inlet operation and conditions of maximum total-pressure recovery.

Report discussing an investigation to determine the cause and provide a fix for the instability in flight of the antisubmarine rocket Mk 1 Mod 0. The Magnus effects and their nonlinear variation with angle of attack were found to affect the stability, so reducing the Magnus effects should reduce instability in the missiles. The greatest reduction of Magnus effects was found through a combination of nose-ring spoiler and the original direction of the propeller rotation, but the nose ring increased the drag.

An experimental investigation of the aerodynamic characteristics of a slender, square-based body of revolution was conducted at a Mach number of 3.12 for angles of attack from 0 degree to 10 degrees and for Reynolds numbers from 2 x 10(exp 6) to 15 x 10(exp 6). Boundary-layer measurements at zero angle of attack are compared with several compressible flow formulating for predicting boundary-layer characteristics. Comparison of experimental pressure and force values with theoretical values showed good agreement for low angles of attack. The measured mean skin-friction coefficients agreed well with those predicted by Mangler's transformation for laminar flow over cones.

The following report describes the process of the determination of hydrogen in magnesium, lithium, and magnesium alloys, including methods of analyzing magnesium-lithium alloys for hydrogen, and the tin-fusion method used for determining the hydrogen content of pure magnesium that can also be used to analyze pure lithium for hydrogen.

The permeability characteristics and tensile strength of a porous material developed from stainless-steel corduroy wire cloth for use in transpiration-cooled walls where the primary stresses are in one direction were investigated. The results of this investigation are presented and compared with similar results obtained with porous sintered metal compacts. A much wider range of permeabilities is obtainable with the wire cloth than with the porous metal compacts considered and the ultimate tensile strength in the direction of the primary stresses for porous materials produced from three mesh sizes of wire cloth are from two to three times the ultimate tensile strengths of the porous metal compacts.

Report discussing an investigation into the ability of human pilots to control short-period yawing oscillations using a yaw simulating device. The ability to control the oscillations was determined to be a function of period, control effectiveness, and inherent damping. Pilot control effectiveness was found to improve with practice.

"This report briefly summarizes some of the available information on fuels for gas-turbine powered aircraft. The effects of fuel volatility and composition on the range, reliability, and safety of aircraft are discussed. Availability is briefly considered for fuels at various volatility levels" (p. 1).