Describes all uses of sphagnum moss in plant propagation.

Report presenting a free-jet investigation of the performance, burner-shell cooling, and ignition characteristics of a flight-weight 48-inch-diameter XRJ47-W-5 ramjet engine at an inlet Mach number of 2.75 and an angle of attack of 3 degrees. Data were obtained over a range of altitudes, inlet temperatures, and fuel-air ratios.

Memorandum presenting a supersonic wind-tunnel investigation of the origin and distribution of store interference performed in the 4- by 4-foot supersonic pressure tunnel at Mach number 1.6. Separate forces on a store, a fuselage, a swept wing, and a swept-wing-fuselage combination were measured. The configuration investigated simulated a heavy bomber airplane with a large store or nacelle with frontal area equivalent to a twin-engine nacelle.

From Summary: "A preliminary experimental investigation is being conducted to determine the feasibility of preventing rain from impinging on aircraft windshields by means of high-velocity jet-air blast. The results indicate that rain deflection by jet blast appears feasible for flight speeds comparable with landing and take-off speeds of interceptor-type jet aircraft; however, attainment of good visibility through the mist generated by raindrop breakup presents a problem. For the simulated windshield and the lower windshield angles used in the investigation, air-flow rates of the order of 3.3 pounds per minute of unheated air per inch of windshield span were required for adequate rain deflection at a free-stream velocity of 135 miles per hour."

Report presenting an investigation using rocket-propelled models in free flight to determine the external drag and pressure recovery of the NACA 1-40-250 nose inlet at zero angle of attack.

Report presenting an investigation of 2,2,5-trimethylhexane, 2,2-dimethylbutane, and 3-heptane in regards to their susceptibility to vapor-phase oxidation and their oxidation products.

Experimental data obtained from three shielded and three unshielded thermocouple probes are presented. Data taken in air at room temperature over the ranges 0.2 to 2.2 Mach number and 0.2 to 2.2 atmospheres total pressure show reproducible systematic variations of recovery with Mach number, ambient pressure, flow angle, and probe design. Time-constant data determined at Mach 0.2 and room temperature and pressure indicate that unshielded probes are several times faster in response to temperature changes than shielded probes.

Because the Weissinger seven-point results were found to be in error for wings combining high aspect ratio with large amounts of sweep, a simple procedure is demonstrated which corrects errors and results in more accurate span loadings read directly from loading charts. The procedure consists of an alteration of the taper ratio used plus an additional correction applied at the wing root.

Results are presented of tests to determine the effect of heating at uniform temperature rates from 0.2 degrees to 100 degrees F per second on the tensile properties of 7075-T6 d(75s-T6) and 2024-T3 (24s-T3) aluminum-alloy sheet under constant-load conditions. Yield and rupture stresses, obtained under rapid-heating conditions, are compared with results of elevated-temperature stress-strain tests for 1/2-hour exposure. Master yield-and-rupture-stress curves based on linear temperature-rate parameter are presented. Yield and rupture stresses and temperatures may be predicted by means of master curves and the parameter.

Report presenting a general matrix method for the solution of characteristic-value problems of the type arising in many physical applications. The matrix is applied to the problem of finding criticality and neutron fluxes in a nuclear reactor with control rods. The two-dimensional finite-difference approximation to the two-group neutron-diffusion equations is treated.

Report presenting testing of heat-treated cast HS-21 turbine blades to determine the effect on the service life by running the blades to failure in a J33-9 turbojet engine. The heat treatment effects were found to depend on the initial structure of the cast blades. Results regarding engine operation, metallurgical studies of as-cast and heat-treated blades, and metallurgical studies of failed blades are provided.

Report presenting surface temperature distributions on a hollow cylinder aligned with the airstream was studied in a Mach 3.12 wind tunnel at a range of Reynolds numbers. Transition with and without single roughness elements was observed from surface temperature distributions and high-speed schileren motion pictures. Results regarding pressure distributions, recovery-factor distributions, high-speed schileren motion pictures, transition Reynolds number, heat-conduction effects, and a qualitative description of observed flows are provided.

Note presenting tables of coefficients which facilitate the stress analysis of circular semimonocoque cylinders with cutouts by the method published in a previous report. When the values of two simple structural parameters are known, use of the coefficients enables shear flows and stringer loads in the neighborhood of a cutout to be calculated.

From Introduction: "The present paper contains a first-order evaluation of a number of aerodynamic derivatives for a rectangular wing of infinite aspect ratio at finite angles of attack, based upon the linear perturbation theory for rotational flow."

Report presenting the results of a wind-tunnel investigation of a series of models of nine related horizontal tails to provide basic design information, including the effects of aspect ratio, sweepback, and changes in the Mach number, and to provide experimental values of the lift and hinge-moment parameters for comparison with values computed by a method employing lifting-surface theory.

Report presenting the application of the techniques of generalized harmonic analysis to the airplane taxiing problem. Some previous results on runway roughness are reviewed and some results obtained from taxiing tests of a large airplane are given. The use of spectral techniques was found to be a rather concise way of presenting the characteristics of runway roughness.

Report presenting the measurement of effective flame speeds of free turbulent flames using photographic, ionization-gap, and photomultiplier tube methods and were found to have a statistical distribution attributed to the nature of the turbulent field.

Report presenting equations that are extended to include corner effects when evaluating gas-flow interferometry. A simple method for evaluating the density adjacent to a surface is described.

Report presenting the effect of compressibility on the loss characteristics downstream of two-dimensional turbomachine blade rows. In this particular example, increasing the trailing-edge thickness increased the overall loss coefficients significantly, with an effect of compressibility only at exit flow angles close to axial.

The models, apparatus, and instrumentation developed for investigations of the rough-water characteristics of seaplanes in the Langley tanks are described briefly. The results of several investigations to improve these characteristics are combined and summarized. The large effect of waves in take-off resistance is illustrated. The general relationship of the measured quantities of importance to wave length and height are also illustrated.

"Charts published in NACA TN 3323 for estimating the performance of high-performance helicopters were applicable to rotors having hinged rectangular blades with a linear twist of -8 degrees. Supplementary charts are presented herein covering twists of 0 degrees and -16 degrees" (p. 1).

Report presenting relations for the calculation of heat transfer at the forward stagnation point of both two-dimensional and axially symmetric blunt bodies. The relations for the heat transfer, which were obtained from exact solutions to the equations of the laminar boundary layer, are presented in terms of local velocity gradient at the stagnation point.

Note presenting an investigation of the profiles and thicknesses of normal shock waves of moderate strength in terms of the variation of the equilibrium temperature of an insulated transverse cylinder in free-molecule flow. The shock waves were produced in a steady state in the jet of a low-density wind tunnel, at initial Mach numbers of 1.72 and 1.82 in helium and 1.78, 1.85, 1.90, 1.98, 3.70, and 3.91 in air. Results regarding the free-molecule probe response in a uniform stream, operation of normal shock holders, normal-shock-wave profiles, shock-wave thicknesses, evidence of wire-size effect on shock-wave profile, and the potential of experimental error are provided.

Report presenting the flow characteristics of a series of rectangular outlets which discharge air into the transonic stream together with wall static-pressure distributions in the vicinity of the outlets, as well as thrust coefficients of rectangular and circular outlets. Results regarding the discharge coefficients, surface pressure distribution, vent pressures, and thrust coefficients are provided.