Report presenting an exact solution and a closely concurring approximate energy solution for the buckling of an infinitely long flat plate under combined shear and transverse direct stress with edges elastically restrained against rotation. An appreciable fraction of the critical stress in pure shear may be applied to the plate without any reduction in the transverse compressive stress necessary to produce buckling.

Abstract. thorium can be precipitated as a salt of p-dimethylaminoazophenylarsonic acid at a pH of about 1.5. the precipitate, collected on a sintered glass filter is washed with dilute ammonium hydroxide to dissolve the dye. the amount of thorium is determined by measuring the concentration of the dye spectrophotometrically at a wavelength of 450 millimicrons. Zirconium, which interferes, can be separated and determined using the same reagent in strong hydrochloric. the behavior of thorium metal upon treatment with various acids and upon fusion withKHSO4 is described. three satisfactory procedures are given for dissolving the metal with sulfuric acid, phosphoric acid, and by a potassium hydrogen sulfate fusion. The laboratory was presented with the problem of analyzing for a large number of elements in O2 metal. the results of a systematic study of methods for effecting solution of the metal are offered here since they may be of some interest and use to other laboratories. The four methods which effected complete solution of the metal are (1) Sulfuric acid method; (2) Fusion method; (3) Phosphoric acid method; and (4) Nitric acid-hydrofluoric acid method.

Abstract. Some rather idealized considerations are given regarding the depth a warped rod presses into the ribs at the places of contact. It appears that this distance may, under some conditions, be of the order of 70 times greater than for a straight rod resting uniformly on the ribs.

Report discussing the results of an investigation of a test for statistical consistency of counter-scaler units.

Introduction: This report embodies the results of an investigation as to the possibility of removing the bulk of the iron from gunk solutions of various concentrations by precipitation of the iron with phthallic acid and subsequent precipitation of tuballoy. The method consists of dissolving the phthallic acid in the gunk solution and then adding NH₃ to a suitable pH, precipitating the iron, and leaving the tuballoy in solution.

Report presenting an analysis of available data on vee-tail surfaces. The analysis indicated that a vee tail designed to provide values of stability and control parameters equal to those provided by a conventional tail would probably provide no reduction in area unless the conventional vertical tail is in a bad canopy wake or unless the vee tail has a higher effective aspect ratio than the conventional vertical and horizontal tails.

Report presenting an analysis of the effect of wing loading of the landing flare, which indicated that it had an important effect on landing technique and distance. Results regarding the approach and flare path and ground run are provided.

"Flight measurements have been made of the individual aileron hinge moments, aileron rolling effectiveness pb/2V ,and stick-force characteristics in abrupt aileron rolls with a P-40F airplane (AAF No. 41-14119) over an indicated airspeed range from 108 to 304 miles per hour. Three methods for measuring the rate of change of hinge moment with angle of attack were investigated. Presented for comparison with the flight results are data from two-dimensional wind-tunnel tests of the wing-aileron profile as measured at the center aileron hinge" (p. 1).

Report presenting tests to determine the critical shear stress of curved sheets. The empirical formula derived from the tests is applicable to panels with a ratio of radius to thickness of 300 or greater, a central angle of 1 radian or less, and a ratio of arc length to axial length not greater than 1.

Charts are presented that permit the estimation of F-3 and F-4 knock-limited performance ratings for certain ternary and quaternary fuel blends. Ratings for various ternary and quaternary blends estimated from these charts compare favorably with experimental F-3 and F-4 ratings. Because of the unusual behavior of some of the aromatic blends in the F-3 engine, the charts for aromatic-paraffinic blends are probably less accurate than the charts for purely paraffinic blends.

Calculations based on dynamometer test-stand data obtained on an 18-cylinder radial engine were made to determine the improvement in fuel consumption that can be obtained at various altitudes by gearing an exhaust-gas turbine to the engine crankshaft in order to increase the engine-shaft work.

Report discussing testing of the Douglas A-26B to determine the lateral and directional stability and control characteristics. Information about the control-free lateral and directional oscillations, sideslip due to full aileron deflection, control-fixed and control-free directional stability, effective dihedral, side force due to sideslip, rudder control characteristics, variation of rudder and aileron force with speed, and response to abrupt aileron deflection are described.

Report discussing testing on the Douglas A-26B airplane to determine the stalling characteristics, variation of maximum normal-force coefficient with flap position, and a calibration of the service airspeed installation.

Report discussing tests of the drag clean-up and stability of the Bell YP-59A jet-propelled airplane. The general stability, static stability, and control characteristics were examined. Specific details are also included about the effects of the exhaust jet on air flow at the tail.

Report presenting an investigation of planing devices like hydroflaps and hydrofoils on several dynamically scaled models of military airplanes and their effectiveness in improving ditching characteristics. The ditching aids were generally found to be of value. Results regarding the hydroflap test in the impact basin, dynamic model tests at the outdoor catapult, and effect of ditching aids on ditching performance and rough water are provided.

Report presenting an extension of previously reported data on the variation of maximum lift coefficient with Mach number, camber, and thickness ratio. The data were obtained from pressure-distribution tests in the 8-foot high-speed tunnel of six propeller airfoils of 1-foot chord.

Report discusses the results of measurements made via an XC-35 airplane to determine the relation between the velocities of vertical drafts and associated gusts within convective-type clouds. Information about vertical-draft velocity and maximum vertical true gust velocity is included.

Report presenting knock-limited small-scale-engine tests of isopropyl-benzene, benzene, and o-xylene blended individually in various concentrations with selected base fuels. Data were obtained to determine the blending sensitivity, lead susceptibility, and sensitivity of the blends to inlet-air temperatures. Isopropylbenzene was found to be the most effective overall.

Report discusses a method of correlating engine-cooling data and its application to a representative engine-cooling test. Considerations for the correlation method are given, but the application to specific engine-cooling problems should be simple and direct. Information about experimental procedure and an example with specific values are included.

Report providing charts to assist with estimating F-3 and F-4 knock-limited performance ratings for several ternary and quaternary fuel blends. Several unusual behaviors were noted in the F-3 engines using the aromatic-paraffinic blends, so the charts for them may not be as accurate. General trends observed in different types of fuel are also described.

Inroduction: "A study of the literature, particularly the work done by R. Strubl, I.W. Kolthoff and S.B. Smith, indicated that a polargraphic method for the estimation of T could be devised which would not sacrifice reasonable accuracy for rapidity. Work was begun with the intention of developing such a method."

It is the purpose of this report to set forth in detail the ore reserve tonnages of this district as determined from field data and the detailed geologic report of January 1944

"The two-dimensional incompressible potential flow over corrugations and bumps of arbitrary shape is derived by conformal transformation. The results are compared with those obtained by the methods of thin-airfoil theory. Some discussion is included of the flow over bumps that protrude both inward and outward from a wall" (p. 1).

"Equations have been derived for the change in the quantities that define the thermodynamic state of air - pressure, density, and temperature - at an abrupt increase in cross-sectional area of flow of compressible air. Results calculated from these equations are given in a table and are plotted as curves showing the variation of the calculated qualities with the area expansion ratio in terms of the initial Mach number as parameter. Only the subsonic region of flow is considered" (p. 1).