"A method is developed of easily determining the performance of a compressor system relative to that of the power section for a given altitude. Because compressors, reciprocating engines, and turbines are essentially flow devices, the performance of each of these power-plant components is presented in terms of similar dimensionless ratios. The pressure and temperature changes resulting from restrictions of the charge-air flow and from heat transfer in the ducts connecting the components of the power plant are also expressed by the same dimensionless ratios and the losses are included in the performance of the compressor" (p. 119).

The preignition characteristics of the R-2800 cylinder, as effected by fuel consumption, engine operating variables, and spark plug type and condition, were evaluated. The effects on preignition-limited performance of various percentages of aromatics (benzene, toluene, cumene, xylene) in a base fuel of triptane were investigated. Two paraffins (triptane and S + 6.0 ml TEL/gal) and two refinery blends (28-R and 33-R) were preignition rated. The effect of changes in the following engine operating variables on preignition limit was determined: inlet-air temperature, rear spark plug gasket temperature, engine speed, spark advance, tappet clearance, and oil consumption. Preignition limits of the R-2800 cylinder using Champion C34S and C35S and AC-LS86, LS87, and LS88 spark plugs were established and the effect of spark plug deterioration was investigated.

"The hydrodynamic characteristics of a 1/10-size powered dynamic model of the XP5Y-1 flying boat were determined in Langley tank no. 1. Stable take-offs were possible at all practicable positions of the center of gravity and flap deflections. An increase in gross load from 123.5 to 150.0 pounds (21.5 percent) had only a slight effect on the stable range for take-off" (p. 1).

From Introduction: "Data are presented in graphical form to show the engine performance over a range of altitudes from 5000 to 50,000 feet and flight Mach numbers from 0.21 to 0.97. Curves are presented to show the windmilling characteristics of the engine. All engine performance data obtained in the investigation are also presented in tabular form."

Report presenting an experimental and analytical investigation of the flutter of uniform sweptback cantilever wings. The experiments used groups of wings sweptback by rotating and by shearing with angles of sweep ranging from 0 to 60 degrees. Results regarding the experimental investigation and a discussion and comparison of the analytical and experimental results are provided.

The results of power-off force tests and flight tests of a model with a thin unswept low-aspect-ratio wing are presented. The tests were made with the flaps retracted and deflected. The effects on the lateral flight characteristics of decreasing directional stability were noted.

Report presenting a method for the design of supersonic-wind-tunnel nozzles that produce uniform flow over a continuously variable Mach number range without the use of flexible walls. Experimental results from a preliminary investigation of the tunnel are included, including calibration survey of flow, Mach number distributions, and pressure gradients are provided.

An effort to develop a control on the air velocity at the door opening of a fume hood.

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The following report summarizes research done on dissolving uranium from phosphate rock and superphosphate and recovering it from solution in a more concentrated form.

This report follows and experiment that was performed to determine the visual efficiency of a phosphor when bombarded by alpha particles.

Report discussing the progress of the Ames Laboratory in metallurgy for the period from April, 1949 through September, 1949.

The test unit is to simulate the conditions existing in the ``active``section of a pile process tube. This section is loaded with 64 slugs each of length equal to 4.3767 inches, giving an overall active length of 23.34 feet. The figure of 4.3767 inches is the overall length of the aluminum can, rather than that of the slug proper. The calculations tabulated on the accompanying data sheet are representative of the conditions of operation of the ``maximum performance tube`` in the pile. The resistance of a heater element with the specified wall thickness is such as to give a total heating of 552 Kw (corresponding to an 800 mw operating level) with a current of 13,000 amperes flowing through the tube. The heating distribution is a sine curve with a maximum heating of 33.56 Kw/ft. at the center. No attempt will be made to simulate the heating distribution in the aluminum end cap.

The meetings divided into two parts, with reviews of work being done in radiobiology at the University of California by various members of their staff as part one, and, as part two, a meeting conducted by Dr. Shields Warren for Laboratory Directors and their representatives. For the most part papers which were reviewed were summarized material which has appeared in the literature and gave progress to date. Since the purpose of the meeting itself was more for the informal directors meetings, results of the latter are here abstracted.

Technical report regarding he purpose of the investigation was to evaluate the Chicago mass spectrograph as an analytical instrument for solids.