Abstract: This is basically a counting rate meter, with an alarm circuit, operating from four GM tubes as the detecting elements. The Hand Counter comprises four logarithmic counting rate meters working from four GM tubes mounted individually, with associated electronic circuits, in suitable shields with a metal mesh type of window. Both sides of both hands are sampled simultaneously. In the Foot Counter, two GM tubes are separately and mounted in a suitable mesh window shielded with the electronic circuit; the foot counter uses only two counting rate meters, and both feet are sampled simultaneously. Each circuit is built in two parts; two tubes are in the shield and the balance of the circuit is in the electronic unit which is a standard 17" x 13" chassis. Circuit diagrams are included.

"The theory of Lagrangian multipliers is applied to the problem of finding both upper and lower limits to the true compressive buckling stress of a clamped rectangular plate. The upper and lower limits thus bracket the true stress, which cannot be exactly found by the differential-equation approach. The procedure for obtaining the upper limit, which is believed to be new, presents certain advantages over the classical Rayleigh-Ritz method of finding upper limits" (p. 213).

The following report discusses the deposition of radioactive elements during a nuclear fission in the skeleton. Studies are concerned with chronic effects of toxic radiation developing within the bone marrow and decontaminating the cells.

Note presenting damping data obtained from free-flight-tunnel tests of 13 models; the results are analyzed and compared with calculated results. The contributions of the wing, flaps, fuselage, tail surfaces, and power to the damping in pitch and yaw were studied. For complete models, fairly good agreement was obtained between experimental and calculated values for power-off, flaps-neutral conditions.

Note presenting an investigation of the electromagnetic-analogy method used to provide lifting-surface-theory solutions applicable to the determination of aspect-ratio corrections for the slope of the curve of hinge-moment coefficient against flap deflection. A comparison of the results of the present measurements with those of previous tests indicated that the increment of induced downwash at the 0.5-chord line over the value predicted by lifting-line theory is a linear function of the center-of-pressure coefficient.

From Introduction: "A collection balanced-aileron test data is given in reference 1. Reference 2 presents a collection of data applicable to the design of tail surfaces. The results of analyses of data for control surfaces with internal balances, plain-overhang and Frise balances, beveled trailing edges, and unshielded horn balances have already been published in references 3 to 6."

Report presenting the results of experiments with a technique for investigating the spray characteristics of flying-boat models. The forebody of a pointed-step flying boat hull was used for testing, and the effects of varying trim, propeller position, and amount of power were investigated. Either of the two types of spray that emanate from a forebody can limit the gross load of a flying boat depending on the configuration.

Report presenting tests conducted in tank no. 2 on models of an unconventional flying-boat hull called a planing-tail hull to determine the effects on resistance of varying a number of afterbody parameters. The effects of varying length, width, and plan-form taper of the afterbody are explored. Results regarding the effect of decreasing width of the afterbody, effect of increasing length of the afterbody, effect of tapering afterbody, and a comparison of planing-tail hulls with a conventional hull are also provided.

Report presenting a study of the two-dimensional flow of a frictionless, adiabatic, perfect gas inside of a two-dimensional hyperbolic nozzle by using numerical methods.

There is definitely a technical possibility that atomic power may gradually develop into one of the principal sources of useful power. If this expectation will prove correct, great advantages can be expected to come from the fact that the weight of the fuel is almost negligible. This feature may be particularly valuable for making power available to regions of difficult access and far from deposits of coal. It also may prove a great asset in mobile power units for example in a power plant for ship propulsion. On the negative side there are some technical limitations to be applicability of atomic power of which perhaps the most serious is the impossibility of constructing light power units; also there will be some peculiar difficulties in operating atomic plants, as for example the necessity of handling highly radioactive substances which will necessitate, at least for some considerable period, the use of specially skilled personnel for the operation. But the chief obstacle in the way of developing atomic power will be the difficulty of organizing a large scale industrial development in an internationally safe way. This presents actually problems much more difficult to solve than any of the technical developments that are necessary, …

Report presenting a number of calculations of bending-torsion wing flutter at two Mach numbers and a comparison of the results. The results indicated that the effect of compressibility on flutter speed for subsonic speeds with no shocks, although complicated, is relatively small in the usual cases.

A connected account is given of the Possio theory of non-stationary flow for small disturbances in a two-dimensional supersonic flow and of its application to the determination of the aerodynamic forces on an oscillating airfoil. Further application is made to the problem of wing flutter in the degrees of freedom - torsion, bending, and aileron rotations. Numerical tables for flutter calculations are provided for various values of the Mach number greater than unity. Results for bending-torsion wing flutter are shown in figures and are discussed. The static instabilities of divergence and aileron reversal are examined as is a one-degree-of-freedom case of torsional oscillatory instability.

The following report provides information and findings of trace elements recognized in a few placer concentrates from Sweepstakes and Rube Creeks in the Koyuk district of eastern Seward Peninsula, Alaska when old collections were scanned for radioactivity in the spring of 1945.

From Introduction: "It is the purpose of this paper to describe the physical properties that are necessary to specify mixture quality in a system containing fuel and dry air and to evaluate the theoretical rolation between these properties and the physical properties of the mixture."

Report discussing several types of jet-exit designs, including normal, beveled, and unsymmetrical shapes, and their effect on the stability characteristics of the aircraft. No deviation of the jet center line from its exposed path is likely to be obtained if a jet exist is used that is normal to the flow. Having a tilted or asymmetrical exit was found to adversely affect the stability of the aircraft.

Report discussing the characteristics of the jet-motor air-intake duct system for a pursuit-type airplane with modifications to the duct system. Details of its effects on the Mach number, high pressure recovery, drag, and simplicity of the system are provided. Problems regarding the flow condition through the ducts and some potential modifications to prevent further issues are also described.

A summary is given of information on atmospheric electrical discharges to aircraft and associated meteorological conditions. Information is given that is designed to give a fairly comprehensive view of the underlying principles of meteorology and atmospheric electricity. Of special interest to pilots are lists of procedures of flight conduct and aircraft maintenance recommended foe avoiding or minimizing the hazards of disruptive electrical discharges and other severe conditions near thunderstorms.

Note presenting static tests made on machine-countersunk riveted joints in 24S-T, X75S-T, and Alclad 75S-T sheet using A17S-T and 24S-T rivets. In order to intensify the cutting action of the rivets, all specimens were made with the depth of countersink just equal to the thickness of the sheet.

"Column and plate compressive strengths of extruded 14S-T aluminum alloy were determined both within and beyond the elastic range from tests of flat-end H-section columns and from local-instability tests of H-, Z-, and channel-section columns. These tests are part of an extensive research investigation to provide data on the structural strength of various aircraft materials. The results are presented in the form of curves and charts that are suitable for use in the design and analysis of aircraft structures" (p. 1).

Tests were made to determine the effect of brake forming on the strength of 24S-T aluminum alloy sheet that had been formed to an inside bend radius of three times the sheet thickness. The results for both directions of the grain of the material showed that the compressive yield stresses were appreciably increased, that the tensile yield stresses were moderately increased, that the ultimate tensile stresses were only slightly increased, that the elongations were considerably reduced, and that the shapes of the tensile and compressive stress-strain curves were markedly changed.

"A single chart has been prepared that simplifies the calculation of the thermodynamic properties of air, various octene-air mixtures, and mixtures of those with their products of combustion at all temperatures below which chemical dissociation becomes unimportant. The chart is based on the use of 1 pound mol of mixture, and examples of its use are given in the form of the calculation of a turbocompressor power plant and a supercharged Otto engine cycle" (p. 1).

The following report discusses findings resulting from experiments on recycled carbon tetrachloride at various stages of the proposed purification process.

"The well-known methods of thin-airfoil theory have been extended to oblique or sweptback airfoils of finite aspect ratio moving at supersonic speeds. The cases considered thus far are symmetrical airfoils at zero lift having plan forms bounded by straight lines. Because of the conical form of the elementary flow fields, the results are comparable in simplicity to the results of the two-dimensional thin-airfoil theory for subsonic speeds" (p. 267).

Reported are: physics (B Pile, D Pile, F Pile, general physics); and water, corrosion and engineering (process water control and pressure drop studies, corrosion, graphite expansion).