Report that discusses the possibility of testing the T-invariance in μ-meson decay. The author describes a past experiment performed by Lee and Yang, as well as the specifics of the proposed experiment to test the time reversal in μ-meson decay.

It is shown by the author's experiments that hydrogen which escapes to the atmosphere through openings in the system may burn spontaneously if it contains dust. Purely thermal reasoning can not account for the combustion. It seems to be rather an electrical ignition. In order to determine whether the cause of the spontaneous ignition was thermo-chemical, thermo-mechanical, or thermo-electrical, the experiments in this paper were performed.

A method for the solution of the incompressible nonviscous flow through a centrifugal impeller, including the inlet region, is presented. Several numerical solutions are obtained for four weight flows through an impeller at one operating speed. These solutions are refined in the leading-edge region. The results are presented in a series of figures showing streamlines and relative velocity contours. A comparison is made with the results obtained by using a rapid approximate method of analysis.

"Flight tests were made to determine the total-pressure recovery of a split-wing ram-jet inlet with a fixed area exit 20 percent larger than the inlet throat over a Mach number range from 1.4 to 3.16. Total-pressure-recovery measurements at the diffuser exist station indicated abrupt pressure changes in the total-pressure profile throughout the Mach number range. Comparisons of average total-pressure recovery with the theoretical total-pressure recovery showed good agreement" (p. 1).

Memorandum presenting an investigation in the 7- by 10-foot tunnel to determine the effect of wing-root leading-edge- and scoop-type jet-engine air-inlet configurations on the static lateral stability characteristics of a scale model of the MX-1764 airplane. The addition of the inlet configurations to the model generally had only small effects on the lateral stability.

Report presenting initial flight tests of two simplified flutter vehicles. Test results were in agreement with the results of the freely-falling-body test in that the wing failures in the transonic range occurred at velocities greater than the flutter velocity calculated from the two-dimensional theory.

From Introduction: "The investigation covered a range of Mach numbers from 0.66 to 1.12 and included measurements of angle of attack, pitching moment, normal force, and chord force. The drag at zero lift obtained in this investigation was reported in reference 1, but without the correction for tare of the end plate."

An equation for quenching distance based on the destruction of chain carriers by the surface is derived. The equation expresses the quenching distance in terms of the diffusion coefficients and partial pressures of the chain carriers and gas phase molecules, the efficiency of the surface as a chain breaker, the total pressure of the mixture, and a constant which depends on the geometry of the quenching surface. Quenching distances measured by flashback for propane-air flames are shown to be consistent with the mechanism. The derived equation is used with the lean inflammability limit and a rate constant calculated from burning velocity data to estimate quenching distances for propane-air (hydrocarbon lean) flames satisfactorily.

In order to insure satisfactory turbine performance under five turbojet-engine operating conditions, turbine design requirements were determined for the following operating conditions: take-off, maximum thrust at altitude, altitude cruising at rated rotative speed, altitude cruising with maximum-thrust exhaust nozzle area, and engine acceleration at 80 percent equivalent design rotative speed. If cruising is to be at rated engine speed, both cruising and take-off should be considered in turbine design. Design requirements for the other conditions are nearly identical. Without compressor-exit bleed, a turbine cannot accelerate this compressor at 80 percent of rated speed; with 28.6-percent bleed, the design requirements are within those for take-off.

"Charts showing the variation in dynamic stability with the rudder hinge-moment characteristics are presented. A stabilizing rudder floating tendency combined with a high degree of aerodynamic balance is shown to lead to oscillations of increasing amplitude. This dynamic instability is increased by viscous-friction in the rudder control system" (p. 147).

Report presenting flight tests to determine the total-pressure recovery of a split-wing ram-jet inlet with a fixed area exit 20 percent larger than the inlet throat over a range of Mach numbers. Total-pressure-recovery measurements at the diffuser exit station indicated abrupt pressure changes in the total-pressure profile throughout the Mach number range.

Report presenting an investigation in the 300 mph 7- by 10-foot tunnel to determine the effect of wing-root leading-edge- and scoop-type jet-engine air-inlet configurations on the static lateral stability characteristics of a scale model of the MX-1764 airplane. The inlet configurations generally had only small effects on the lateral stability.

From Summary: "A thermodynamic relation is derived and simplified for use as a temperature-limiting control equation involving measurement of gas temperature before combustion and gas pressures before and after combustion. For critical flow in the turbine nozzles of gas-turbine engines, the control equation is further simplified to require only measurements upstream of the burner. Hypothetical control systems are discussed to illustrate application of the control equations."

"An analysis is made of the structural response to gusts of an airplane having the degrees of freedom of vertical motion and wing bending flexibility and basic parameters are established. A convenient and accurate numerical solution of the response equations is developed for the case of discrete-gust encounter, an exact solution is made for the simpler case of continuous-sinusoidal-gust encounter, and the procedure is outlined for treating the more realistic condition of continuous random atmospheric turbulence, based on the methods of generalized harmonic analysis. Correlation studies between flight and calculated results are then given to evaluate the influence of wing bending flexibility on the structural response to gusts of two twin-engine transports and one four-engine bomber" (p. 1).

The susceptibleness of certain "ceramic" substances to extreme radiation damage (such as that observed in graphite) as indicated by changes in dimensions and heat content is discussed in terms of the experimental evidence which is available.

From Scope of Investigation: "The work reported here is part of a continuing program concerning the long-term volume changes in concretes made from lightweight and normal-weight aggregates. The creep, drying-shrinkage, and strength data presented are for concretes made with 24 expanded shale lightweight aggregates and 5 natural, normal-weight aggregates. These aggregates were from widely separated geographical locations and were to be representative samples of aggregates being used in the production of structural concretes."

From Introduction: "The object of this research was to identify and study some of the factors involved in premature failures and to relate the pertinent factors to roof performance."

Abstract : Methods for the chemical separation of strontium, barium, cesium, cerium, yttrium, zirconium, niobium, and tungsten from complex matrices are described. Procedures for the radiometric determination of the longer-lived isotopes of these elements are outlined. Inert carriers are added and the sample is dissolved by fusion with sodium carbonate. The melt is leached first with water and then with hydrochloric acid. The elements are recovered from these fractions by a series of wet chemical and ion exchange procedures, and gravimetric and radiometric determinations performed.

"The influence of automatic operation of the aileron and rudder controls on the lateral stability of an airplane is discussed. The control deflections are assumed to be proportional to the deviations and to the rates of deviation of the airplane from steady-flight conditions. The effects of changes in the types of deviation governing control application are considered. For one simple method of control in which the aileron deflection is proportional to the angle of bank and the rudder deflection is proportional to the angle of yaw, the effect of lag in control application is studied and regions of stability with and without lag are given" (p. 273).

The available foreign and American data relating to Reynolds number effects on the maximum lift coefficients of swept-back wings are summarized and discussed. The data show that at low Reynolds numbers (below about 2.0 x 10(exp 6)) higher maximum lift coefficients were measured in most cases for moderately swept-back wings than for unswept wings of similar plan form; at high Reynolds numbers, however, increasing sweepback resulted in decreasing maximum lift coefficients. A smaller rate of increase of the maximum lift coefficient with Reynolds number was measured for the swept-back wings than for similar unswept wings in the critical range of Reynolds number. Increasing the Reynolds number resulted in decreases in the maximum lift coefficients of the two wings of approximately triangular plan form that were investigated.

Report presenting an investigation to determine the reductions in temperature-recovery factor associated with pulsating flows generated by spike-nose cylinders. The investigation was conducted at zero angle of incidence at a free stream Mach number of 3.50 and a free stream Reynolds number of 1.73 million.

Report presenting an investigation of the jet effects on several afterbody shapes of a single-engine fighter-airplane model in the 16-foot transonic tunnel at a range of Mach numbers and angles of attack. The afterbody-geometry variables were boattail angle, afterbody length, and base area. Results regarding evaluation of support interference, afterbody-pressure-distribution characteristics, and drag characteristics are provided.

From Summary: "In order to improve the tracking characteristics of an automatic interceptor, a revised roll-command computer was tested both on an analog computer and in flight. This report presents flight-test results which indicate a significant improvement in flight-path stability and tracking accuracy. The modified roll computer was designed on the basis of previous analytical studies."

Report presenting an investigation of a free-flight test vehicle to obtain boundary-layer-transition and heat-transfer data. The model had a 15-degree-included-angle cone-cylinder and a 10 degree conically flared afterbody. Results regarding the free-stream conditions, conditions at outer edge of boundary layer, temperatures and heat-transfer coefficients, and boundary-layer stability conditions are provided.