This report is about the Efficiency Rating Systems Preliminary Report

Report presenting a method for predicting the amplitude and frequency, under certain simplifying conditions, of the hunting oscillations of an automatically controlled aircraft with lag in the control system or in response of the aircraft to the controls. Formulas are given expressing the response to a variation of signal in terms of response to a unit signal.

Summary: The effective change in the velocity of flow past a wing section, caused by the presence of wind-tunnel walls, is known for potential flow. This theory is extended by investigation of the two-dimensional compressible flow past a thin Rankine Oval. It is shown that for a symmetrical section at zero angle of attack the velocity increment due to the tunnel walls in the incompressible case must be multiplied by the factor 1/1-M^2 to take account of compressibility effects. The Mach number, M, corresponds to conditions in the wind-tunnel test section with the model removed (p. 1.).

"An analysis was made to show the relative effectiveness of streamline external fuel tanks, a fuel tank in the form of a wing mounted in a biplane position, and auxiliary wing panels attached at the wing tips to increase the span as temporary means for increasing the range of a fighter-type airplane. Figures and charts for the various devices considered show the results of calculations of range, duration of flight, and take-off distance for both land-base and carrier operation. The results indicated that the wing-tip extensions were the most promising of the devices considered" (p. 1).

Report discusses the results of an investigation to determine the feasibility of using the change in the specific gravity of fuels in aircraft fuel tanks to measure fuel-vaporization loss. Six fuels were tested via fuel-distillation tests and simulated-flight tests. An equation based on the specific gravity of the fuel is also described.

"The results of flight investigations of the profile drag of several carefully finished conventional and low-drag airfoils are presented. The results indicated that in all cases lower profile-drag coefficients were obtained with the low-drag than with the conventional airfoils over the range of lift coefficient tested and that, for comparable conditions of lift coefficient and Reynolds number, the low-drag airfoils may have profile-drag coefficients which are at least 27 percent lower than the profile-drag coefficients of the conventional airfoils" (p.1).

Report presenting an experimental investigation of rectangular exhaust-gas ejector pump to provide data that would serve as a guide to the design of ejector applications for aircraft engines with marginal cooling. With a decrease in the quantity of air pumped and an increase in the length of an ejector, the ejector pressure rise increases to optimum values. Results regarding straight ejectors, diffuser ejectors, curved ejectors, ejector aspect ratio, divided ejectors, multistage ejectors, and nozzle-exit effects are provided.

Report presenting flight tests conducted to evaluate the effect of a thermal ice prevention system on the aerodynamic performance of a C-46 cargo airplane. The installation of the thermal ice-prevention system was found to reduce the indicated airspeed by about 6 miles per hour. Results regarding the overall performance change resulting from the installation of the thermal system, reduction of power attributed to heat-exchanger exhaust-gas back pressure, reduction of power attributed to the internal and external drag of the thermal system, and the additional airplane gross weight attributed to the thermal system are provided.

Report presenting flight tests to establish the dry-air-performance characteristics of a thermal ice-prevention system at various operating conditions and altitudes. Results regarding twin-engine tests and single-engine tests of characteristics such as skin temperatures and location of heating are provided.

Report containing articles, manuscripts, and tabulations of recorded spectra created by the Spectroscopic Laboratory of the University of Chicago.

Note presenting testing performed on scale models of a modern low-wing monoplane in the 15-foot free-spinning wind tunnel. Results are presented in the form of charts that afford a direct comparison between the spins of the two models for a number of different conditions. The results indicate that, within the range of Reynolds numbers used in the present investigation, such factors as difficulty of ballasting and testing are more important in determining proper model size than the changes in scale effect likely to result from the use of different sizes of models.

Report issued by the Bureau of Mines over the progress made in emergency mine communications. The results of testing done on low-frequency radio communication are presented. This report includes tables, graphs, illustrations, and photographs.

Report issued by the U.S. Bureau of Mines over magnetic surveys conducted on the Florida peninsula. Measurements, methods, and instrumentation used for the survey are presented. Tables and maps are included in this report.

Report issued by the U.S. Bureau of Mines on exploration of kaolin clay deposits for alumina. Properties of the kaolin clay and alumina recovered are listed. This report includes tables, graphs, and illustrations.

Report issued by the U.S. Bureau of Mines on magnetic surveys conducted on Worcester County, Maryland. The results of observations obtained on the ground and from the air are presented. This report includes tables, graphs, and maps.

Report issued by the U.S. Bureau of Mines on the increase of pig-iron during steel production. The machinery, organization, and methods used in the study are presented. This report includes tables, graphs, and photographs.

Report containing articles, manuscripts, and tabulations of recorded spectra created by the Spectroscopic Laboratory of the University of Chicago.

This report gives a short summary of each of the following programs: (1) 184-inch Cyclotron Program; (2) 60-inch Cyclotron Program; (3) Synchrotron Program; (4) Linear Accelerator Program; (5) Experimental Physics; (6) Theoretical Physics; (7) Chemistry; (8) Medical Physics; and (9) Health Physics and Chemistry.

The radioactive amino acid's synthesized from C{sup 14}O{sub 2} by green algae both in the light and in the dark after CO{sub 2}-free preillumination have been separated and identified using paper chromatography and radioautography. The radioactive amino acids identified were aspartic acid, alanine and smaller amounts of 3- and 4-carbon amino acids. This finding as well as the total absence of radioactive glutamic acid substantiates the mechanism for reduction of CO{sub 2} previously postulated by members of this laboratory.

This report discusses the Production Test 105-2-P (Supplement A) -- Activity of Pile Discharge Water. Previous studies of pile discharge water have shown that one of two processes is responsible for the large but variable amount of Mn{sup 56} activity present in the water. One process is the production of Mn{sup 56} by the reaction Mn{sup 55} on manganese impurity in the water. The amount of such impurity has been shown to be too small to produce the observed amount of Mn{sup 56} unless the mean irradiation time is increased by a large factor due to temporary sticking of manganese on the surfaces in the tubes. The other process is the production by the reaction Fe{sup 56} on iron in the film. The present production test was designed to determine which of these processes is responsible for the troublesome Mn{sup 56} activity and to what extent the activity is increased due to sticking of manganese or iron in the tubes. 4 figs.

Description of the standards used by the electrical power industry for the measurement of the electrical quantities.

The following report examines the fission counter, fission plates and activation results of the neutron energy distribution in the center of the Los Alamos plutonium reactor.

The operation of the Fast Reactor is considered in terms of normal equilibrium conditions and normal shut-down. The proposed loading, control rod adjustment and subsequent "floating" operation are discussed. Safety devices and interlocks are described. Temperature and reactivity changes are examined with respect to various system failures, phase changes, and "flashing" of the reactor. Slow changes due to faulty slug cooling are also considered. The calculations were initially based upon 10 kw operation. Performance tests of the mercury system now indicate that 20-kw operation may be feasible.

The following report describes procedures taken to utilize the photelometer to procure the most rapid and reliable determinations, but the goal of the tests presented was to create satisfactory dispersions of particles to analyze.