Summary: "Criticality was considered impossible in any contingency encountered in practice under either of the following conditions which include no safety factor: (a) In any isolated cylinder not more than 5 in. in disruptor, if the total amount of U235 present does not exceed 7.5 Eg. (b) In an isolated vessel of any shape and size, if the total amount of U235 present does not exceed 880 g. An "isolated" vessel is one which does not "see" more than 0.1 [...] other vessels containing fissionable material."

Report presenting a wind-tunnel investigation to determine the effects of leading-edge radius and maximum thickness-chord ratio on the variation with Mach number of the aerodynamic characteristics of several thin symmetrical NACA 4-digit-series airfoil sections. The variations with Mach number of the lift, drag, and pitching moment for a 4-percent-chord-thick airfoil section are not significantly affected by a change of leading-edge radius from 0.18 to 0.53 percent of the chord. Results regarding the leading-edge radius effects and maximum thickness-chord ratio are provided.

Memorandum presenting an investigation conducted in the 4- by 4-foot supersonic tunnel to determine the longitudinal stability and control characteristics of a model of a supersonic airplane configuration at Mach number 1.40. The model had a 40 degree sweptback wing with 10-percent-thick circular-arc sections normal to the quarter-chord line. The results indicated a high degree of longitudinal stability that was fairly constant throughout the trim-lift-coefficient range.

Report presenting a correlation of carbon deposition of 19 fuels in a turbojet combustor as a function of the boiling point and of the flame height at the sooting point of the fuels in a simple wick lamp for a particular combustor operating at a single set of conditions. Two similar investigations with different combustors, operating conditions, and nine different fuels yielded similar correlations on the same graph.

Report presenting the results of tests of four model wings of aspect ratios 1, 2, 4, and 6 and with NACA 65(sub 1)-210 sections. The experimental lift-curve slope is compared with predictions from theory. Results regarding lift, drag, and pitching moment, lift-curve slope, drag divergence, minimum drag, and pitching moment are provided.

Report presenting an investigation in the altitude wind tunnel to determine the operational characteristics of a J47 turbojet engine over a wide range of simulated flight conditions at a range of altitudes. Operational characteristics investigated include operating range, starting, altitude and airspeed compensation of the fuel regulator, and acceleration.

Data are presented for the fundamental flame velocities of 10 pure alkadienes that have isolated, conjugated, or cumulative double-bond systems. On the basis of this limited amount of data and the flame velocities previously reported, it is concluded that unsaturation changes the flame velocity in the order alkanes ? alkenes ? alkadienes with isolated double bonds ?= alkadienes with conjugated double bonds ? alkadienes with cumulative double bonds ?= alkynes. There were no significant differences in the flame velocities of cis and trans 1,3-pentadiene. The alkadienes 1,2-pentadiene and 2,3-pentadiene, with different positions of the cumulative double bond in the straight chain, have similar flame velocities. Methyl substitution in a hydrocarbon reduces the flame velocity; the extent of the reduction increases with the degree of unsaturation of the hydrocarbon.

Report presenting a method of generating variable Mach number supersonic flow in a channel of fixed geometry by the removal of air through uniform porous walls. Calculated porosity distributions are presented for several minimum-length nozzles designed to operate at Mach numbers up to 2.0. Experimental and analytical data is presented.

Report presenting an experimental investigation of thrust augmentation by bleedoff using a 4000-pound-thrust turbojet engine at zero flight-speed, sea-level conditions. Secondary combustion air was bled off from combustion chambers and discharged from an exhaust nozzle and water was then injected into the combustion chambers to replace the bleed-off air. Results regarding the thrust characteristics, engine power, and augmented thrust ratio are provided.

From Summary: "By application of a hyperbolic approximation to the form of the bow waves caused by blunt leading edges on an infinite cascade of supersonic blades, the approximate losses in relative total pressure due to the external bow-wave system arising from blunt edges and subsonic axial entrance velocities were computed. The losses increase linearly with leading-edge radius for any given relative Mach number. For a relative Mach number of 1.60, leading-edge radii may be approximately 1.5 percent of the normal blade gap with a 1-percent loss of relative total pressure."

Report presenting an investigation at transonic speeds in the high-speed 7- by 10-foot tunnel to determine the effect of wing sweep on the maximum-lift characteristics of a series of wings with aspect ratio 4, taper ratio 0.6, and NACA 65A006 airfoil sections. Testing occurred over a range of Mach and Reynolds numbers. Maximum lift coefficients were found to increase with increased sweep at lower Mach numbers but decreased with increase sweep at higher Mach numbers.

Report presenting the results of an investigation at transonic speeds by the wing-flow method of the longitudinal stability characteristics of a 42.8 degree sweptback supersonic airplane configuration. Lift, pitching-moment, and rolling-moment characteristics of the semispan model as well as stabilizer hinge moments and effective downwash at the tail were measured over a range of Mach numbers. The wing-flow data is compared to data for the same configuration from other research facilities.

Report presenting an investigation at conditions of zero ram and seal-level pressure to determine the effect of inlet temperature and humidity on turbojet engine performance with injection of water and water-alcohol mixtures at the compressor inlet.

"Temperature surveys were made at the combustion-chamber outlets of a British Rolls-Royce Nene II engine. The highest mean nozzle-vane and mean gas temperatures were found to occur at a radius approximately 75% of the nozzle-vane length from the inner ring of the nozzle-vane assembly. Variations in engine speed, jet-nozzle area, simulated altitude, and simulated flight speed altered the temperature level but did not materially affect the pattern of radial temperature distribution" (p. 1).

This paper presents a critical comparison made between experimental and theoretical results for the aerodynamic characteristics of wings at supersonic flight speeds. As a preliminary, a brief, nonmathematical review is given of the basic assumptions and general findings of supersonic wing theory in two and three dimensions. Published data from two-dimensional pressure-distribution tests are then used to illustrate the effects of fluid viscosity and to assess the accuracy of linear theory as compared with the more exact theories which are available in the two-dimensional case. Finally, an account is presented of an NACA study of the over-all force characteristics of three-dimensional wings at supersonic speed.

Summary: "Six different types of solutions of various concentrations were used to deoxidize uranium chips on a laboratory scale. None of the solutions tested appears to be more desirable than 50% nitric acid for deoxidizing uranium chip on a production scale."

The following report contains two parts on the analysis of astatine, neptunium and plutonium. Part A discusses a bent crystal focusing X-ray spectrometer that has been designed and built for the observation of the X-and gamma-rays emitted in association with radioactive decay. The instrument uses proportional counter detection and is described, as well as associated electronic circuits. The plutonium L X-rays from Cm-242 and the neptunium L X-rays from Am-241 have been measures. Values of the energies and abundances are reported. Then in Part B, it discusses some isotopes of astatine hitherto unreported that have been observed in bombardments of bismuth on the University of California 184" cyclotron.

The following report is meant to record the premises upon which the site plan for the NTR is already established.

Equations are derived for the rates of heating of objects in induction furnaces and for the maximum temperatures attainable. The equations are primarily useful in designing conducting crucibles, shells, and cylinders so as to increase the power input and decrease heat losses. A very brief treatment is given of the factors which influence the current in the induction coil. The performances of various induction furnaces are compared.