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- Chemical Research -- U233 Production and Extraction; Report for the Month Ending June 21, 1943
- Abstract. The precipitation of Pa233 with MnO2 from a solution of thorium nitrate has been studied in some detail and seems quite satisfactory up to 36 gm Th(HO3)4 4H2O per 100 cc solution. The concentration of Pa233 with respect to the manganese dioxide carrier and the thorium precipitated with the carrier appears to be accomplished quite well by either a series of MnO2 cycles or thorium iodate cycles. Volatility methods for both the separation of Pa233 from the original thorium and for its separation from MnO2 are now under investigation. It has been decided that thorium carbonate will the the thorium compound used in the pile at Site X.
- Coke from Low-Ash Appalachian Coals for Carbon Electrodes in Aluminum Industry with a Chapter on Comparison of Results Obtained by Trent Process for Cleaning Coal with Those by Float-and-Sink Methods
- Report issued by the U.S. Bureau of Mines on testing conducted on coking coal samples for carbon electrode use in aluminum production. The testing methods, and results are presented. This report includes tables.
- A Colorimetric Method
- From abstract: "This paper gives a method for determining Uranium using sodium cresotate as a colorimetric reagent. A precision is obtained of better than 2%. In carrying out analyses for Uranium in corrosion products by existing methods such as ignition to the oxide, silver reductor, or titration with ceric sulfate, it became apparent that a rapid, fairly accurate method for determining uranyl ion would be of great value. Such a method is described in this paper. The most logical color to use is that given by the ferrocyanide complex, but upon studying this, it proved to be unsatisfactory. Sodium salycilate also gives a color which has been used with some success, but its color appears to fade and is not very sensitive. A similar compound, sodium cresotate, was found to give an orange-red color and is the reagent used in the method to be described."
- Column Strength of Magnesium Alloy AM-57S
- Tests were made to determine the column strength of extruded magnesium alloy AM-57S. Column specimens were tested with round ends and with flat ends. It was found that the compressive properties should be used in computations for column strengths rather than the tensile properties because the compressive yield strength was approximately one-half the tensile yield strength. A formula for the column strength of magnesium alloy AM-57S is given.
- A Comparative Study of the Effect of Wing Flutter Shape on the Critical Flutter Speed
- Report presenting a comparison of the results of calculations of the critical flutter speeds of nine uniform rectangular wings without ailerons by two methods: one in which the effect of the wing flutter shape is introduced indirectly by choosing mean values for the wing parameters and one that introduces an additional degree of freedom in the wing-bending flutter mode.
- Comparative Yields of Light Oil, Tar, and Constituents from Carbonization Tests at 800 Degrees, 900 Degrees, and 1,000 Degrees Celsius
- Report issued by the U.S. Bureau of Mines on testing done on a variety of American coals collected from 32 coal beds across the country. The carbonizing properties of samples tested at 3 different temperatures are presented. This report includes tables, and graphs.
- A comparison at high speed of the aerodynamic merits of models of medium bombers having thickened wing roots and having wings with nacelles
- Report presenting testing of models of medium-bomber designs to investigate the relative characteristics of thickened wing roots with propeller-shaft fairings and wings with nacelles. Incremental drag coefficients due to thickened wing roots and due to propeller-shaft fairings through a range of Mach numbers at lift coefficient 0.10. Results regarding force tests, pressure-distribution tests, effect of thickening and filleting, nacelles and propeller-shaft fairings, and a comparison of submerged engines and engine-nacelle combinations are provided.
- Comparison of various methods for computing drag from wake surveys
- "The various equations for computing profile drag by the momentum method are examined, and the errors arising from complete or partial neglect of compressibility effects in the Jones equation and the Bicknell equation are evaluated. The integrating method of Silverstein and Katzoff is shown to be accurate over a wide range of Mach number and wake shapes" (p. 1).
- Construction of Wire Strain Gages for Engine Application
- Report presenting instructions for winding, baking, and mounting a phanolic resin-impregnated, bobbin-type wire strain gage that consists of Advance wire wound around a paper form. A description of some test equipment useful for establishing the merits of the techniques used in gage construction has been included.
- The Contamination of Cooling Water by a P-9 Plant
- The following sources of contamination in cooling water of the P-9 plant are considered: (1) Fission recoils, (2) Corrosion of metal, (3) Recoil from aluminum, (4) Induced activity in the water. It is found that for a P-9 plant of 3.5 x 10(4) KW contamination of the river at "X" should not exceed the .1 r criterion unless coating failure occurs. Tables of the amount of coating failure permissible are given as a function of holdup time.
- Correlation of single-cylinder cooling tests of a Pratt and Whitney R-2800-21 engine cylinder with wind-tunnel tests of a Pratt and Whitney R-2800-27 engine
- Report presenting an equation in which it is possible to correlate the cooling characteristics of an engine. Results regarding engine cooling, engine performance, and estimated cooling-pressure-drop requirements are provided.
- A Correlation of the Dimensions, Proportions, and Loadings of Existing Seaplane Floats and Flying Boat Hulls
- Report presenting a study to determine what loadings and proportions have been chosen by designers of seaplanes and flying boats and what, if any, interrelations exist between the loadings and proportions. The characteristics considered include the beam, getaway speed, forebody length, afterbody length, hull length, center of gravity, and brake horsepower necessary.
- The Coso Quicksilver District, Inyo County, California
- From abstract: The Coso quicksilver district, which is in the Coso Range, Inyo County, Calif., produced 231 flasks of quicksilver between 1935 and 1939. The quicksilver mineral, cinnabar, was not recognized in the district until 1929, although the hot springs near the deposits have been known since about 1875...The granitic rock on which much of the sinter rests is considerably altered. The cinnabar was deposited as films and grains in open spaces in the sinter, during one stage in a sequence of hot spring activities that still continues. The amount of sinter in the district is estimated to be about 1,800,000 tons. Although the greater part of this does not contain much cinnabar, the total quantity of such material is large enough to be of interest as a low-grade ore.
- The Coupling of Flexural Propeller Vibrations with the Torsional Crankshaft Vibrations
- The exact mathematical treatment of the problem is possible by replacing the propeller blade by a homogeneous prismatic rod. Conclusions can them be drawn as to the behavior of an actual propeller, since tests on propeller blades have indicated a qualitative agreement with the homogeneous rod. The natural frequencies are determined and the stressing of the systems under the various vibration modes are discussed.
- Critical Compressive Stress for Curved Sheet Supported Along All Edges and Elastically Restrained Against Rotation Along the Unloaded Edges
- "A formula is given for the critical compressive stress for slightly curved sheet with equal elastic restraints against rotation along the unloaded edges. The theory of small deflections is used and the formula reduces to that given by Timoshenko for the case of simply-supported edges. For larger curvatures, a modification of Redshaw's formula to include the effect of edge restraint is suggested" (p. 1).
- Critical shear stress of an infinitely long flat plate with equal elastic restraints against rotation along the parallel edges
- Report presenting a chart for the values of the coefficient in the formula for the critical shear stress at which buckling may be expected to occur in an infinitely long flat plate with parallel edges. An approximate method for the evaluation of the critical shear stress when the elastic restraints on the two parallel edges are not equal is also presented.
- Critical stress for an infinitely long flat plate with elastically restrained edges under combined shear and direct stress
- "A simple interaction curve is presented for evaluating the conditions of combined shear and direct stress under which an infinitely long, flat plate with equal elastic restraints against rotation along the edges will become unstable. The theoretical work that led to the interaction curve is presented in the form of appendixes" (p. 1).
- Critical Stresses for Plates
- Report presenting the basic methods of theoretically calculating the critical stress for plates with elastically restrained edges. Design charts for various types of sections and columns and critical stress for flat plates and curved sheets are provided.
- Data on buckling strength of curved sheet in compression
- Report presenting tests of curved panels of four different thicknesses and with radius-thickness ratios varying from about 150 to infinity. Results are also included from some previous testing.
- Derivation of charts for determining the horizontal tail load variation with any elevator motion
- Report presenting equations relating the wing and tail loads are derived for a unit elevator displacement. The equations are converted into a nondimensoinal form and charts are given that can be used to predict wing- and tail-load-increment variation for any type of elevator motion and for degrees of airplane stability.
- Description of Stress-Strain Curves by Three Parameters
- "A simple formula is suggested for describing the stress-strain curve in terms of three parameters; namely, Young's modulus and two secant yield strengths. Dimensionless charts are derived from this formula for determining the stress-strain curve, the tangent modulus, and the reduced modulus of a material for which these three parameters are given. Comparison with the tensile and compressive data on aluminum-alloy, stainless-steel, and carbon-steel sheet in NACA Technical Note No. 840 indicates that the formula is adequate for most of these materials" (p. 1).
- Design criterions for the dimensions of the forebody of a long-range flying boat
- Report presenting a correlation of the gross-load coefficient and the forebody length-beam ratio for a limited number of present-day multiengine long-range flying boats for which the spray characteristics are known. Results indicate that the gross-load coefficient for comparable spray characteristics varies as the square of the forebody length-beam ratio.
- Design, selection, and installation of aircraft heat exchangers
- Report presenting a survey of aircraft heat exchangers in three parts: design, selection, and installation. Appendices give the physical properties of air, properties of standard atmosphere as defined by the Navy, Army, and NACA, and an impact-pressure chart.
- Determination of Flight Paths of an SBD-1 Airplane in Simulated Diving Attacks, Special Report
- An investigation has been made to determine the motions of and the flight paths describe by a Navy dive-bombing airplane in simulated diving attacks. The data necessary to evaluate these items, with the exception of the atmospheric wind data, were obtained from automatic recording instruments installed entirely within the airplane. The atmospheric wind data were obtained from the ground by the balloon-theodolite method. The results of typical dives at various dive angles are presented in the form of time histories of the motion of the airplane as well as flight paths calculated with respect to still air and with respect to the ground.
- Determination of General Relations for the Behavior of Turbulent Boundary Layers
- Report presenting an analysis of data for turbulent boundary layers along wings and bodies of various shapes in order to determine the fundamental variables that control the development of turbulent boundary layers. Results indicate that the type of velocity distribution in the boundary layer could be expressed in terms of a single parameter.
- Determination of general relations for the behavior of turbulent boundary layers
- From Summary: "An analysis has been made of a considerable amount of data for turbulent boundary layers along wings and bodies of various shapes in order to determine the fundamental variables that control the development of turbulent boundary layers. It was found that the type of velocity distribution in the boundary layer could be expressed in terms of a single parameter. This parameter was chosen as the ratio of the displacement thickness to the momentum thickness of the boundary layer. The variables that control the development of the turbulent boundary layer apparently are: (1) the ratio of the nondimensional pressure gradient, expressed in terms of the local dynamic pressure outside the boundary layer and boundary-layer thickness, to the local skin-friction coefficient and (2) the shape of the boundary layer. An empirical equation has been developed in terms of these variables that, when used with the momentum equation and the skin-friction relation, makes it possible to trace the development of the turbulent boundary layer to the separation point."
- Determination of the damping moment in yawing for tapered wings with partial-span flaps
- Report presenting a method for determining the damping moment in yawing for tapered wings with partial-span flaps. Charts are given for untwisted wings with various taper ratios, aspect ratios, and center-span flaps. Theoretical and experimental results are provided.
- Determination of the Mass Moments and Radii of Inertia of the Sections of a Tapered Wing and the Center-of-Gravity Line Along the Wing Span
- "For computing the critical flutter velocity of a wing among the data required are the position of the line of centers of gravity of the wing sections along the span and the mass moments and radii of inertia of any section of the wing about the axis passing through the center of gravity of the section. A sufficiently detailed computation of these magnitudes even if the weights of all the wing elements are known, requires a great deal of time expenditure. Thus a rapid competent worker would require from 70 to 100 hours for the preceding computations for one wing only, while hundreds of hours would be required if all the weights were included" (p. 1).
- Development of thermal ice-prevention equipment for the B-17F airplane
- Report presenting a thermal ice-prevention system for the B-17F airplane. The report includes a description of the design, an outline of the design, analysis, and a presentation and discussion of flight-test thermal data secured under non-icing conditions. The basic idea of the design was to raise the temperature of the surfaces to be protected from ice formations by subjecting the inner faces to a stream of heated air.
- Development of thermal ice-prevention equipment for the B-24D airplane
- Report presenting a thermal ice-prevention system for the B-24D airplane. The report includes a description of the design and an outline of the method of design analysis. Results of performance tests of the installation will be presented in a supplementary report.
- Diesel Engines Underground: [Part] 4. Effect on Composition of Exhaust Gas of Variables Influencing Fuel Injection
- Report issued by the Bureau of Mines over diesel engine operations. As stated in the introduction, "it is the purpose of this report to present such data and to reemphasize the importance of adequate maintenance for diesel engines used underground" (p. 2). This report includes tables, and illustrations.
- The Diffusion Length and the Utilization of Thermal Neutrons in a Heterogeneous Pile
- Abstract: "An accurate calculation is given for the quantity which corresponds to the diffusion length in the theory of the pile. The procedure is to establish a relationship between the diffusion length and the change in thermal utilization from a pile with infinite sides to one with sides of a finite length. The calculation of this change in the thermal utilization is then carried through. Approximation to the answer and numerically exact calculations are given in the report. The results show that for radif very near the optimum values the exact diffusion length is slightly larger than the one obtained from the usual formula...However, over most of the range of radii the exact diffusion length is smaller than the approximate one."
- Discriminator for Photographic Analyzer
- Technical drawing of frequency discriminators and image analysis for nuclear reactors.
- Distribution Coefficient of Dâ‚‚O Between Triethylamine and Water
- Summary: "Water containing 1.8% D2O was distributed between the two liquid phases formed with triethylamine at 20 and 35 C. The triethylamine was removed from each phase by aseotropic distillation with benzene before analyzing the water by determining its density with a quartz float. The ratios of the concentrations of the D2O in the water layer to that in the amino layer were 1.007 and 1.004 at 20 and 35, respectfully. The differences from unity are about the same as the errors of analysis."
- Ditching Tests With 1/10-Size Model of the Army a-20a Airplane 1: Calm-Water Tests in NACA Tank No.2
- Report presenting tests to determine the behavior of landplanes when they are forced to land on the water. The report is incomplete.
- Drag Measurements of a Protruding.50-Caliber Machine Gun with Barrel Jacket Removed
- Tests were made in 8-ft high-speed wind tunnel to determine the drag reduction possible by eliminating the barrel jacket of a protruding 50-caliber aircraft gun. It was found that the drag of a standard aircraft gun protruding into the air stream at right angles to the flow can be reduced by 23% by discarding the barrel jacket. At 300 mph and sea-level conditions, this amounts to a decrease in drag of from 83 to 64 pounds. A rough surface finish on the barrel was found to have no adverse effects on the drag of the barrel, the drag being actually less at high Mach Numbers.
- Economic Considerations in the Recovery of Magnesia from Dolomite
- Report issued by the U.S. Bureau of Mines discussing the recovery of magnesia from dolomite. Processes and methods of recovery are described. This report includes tables.
- The effect of altitude on bomber performance
- Report presenting a study devoted to the analysis of the effect of design and operating altitude on the performance of bombers. The primary emphasis is on range performance and charts are presented with range as a function of wing loading, power loading, and design altitude. Results regarding the range at maximum L/D, range at constant power, and performance charts are provided.
- The effect of altitude on cooling
- Report presenting variables that control the cooling of liquid-cooled and air-cooled engines and then to show by illustrations how either engine may be cooled at any desired altitude. Cooling was found to not be the limiting factor in the design of high-altitude airplanes and was also not found to be a valid reason for selecting either liquid- or air-cooled engines for high-altitude operation.
- The Effect of Amphibious Floats on the Power-Off Stability and Control Characteristics of a Twin-Engine Cargo Airplane
- Report presenting power-off wind tunnel tests of a scale model of a twin-engine cargo airplane equipped with amphibious floats. Longitudinal and lateral stability and control characteristics were investigated for three flap positions.
- The Effect of Artificial Aging on the Tensile Properties of Alclad 24S-T and 24S-T Aluminum Alloy
- "An experimental study was made to determine the effect of artificial aging on the tensile properties of alclad 24S-T and 24S-T aluminum-alloy sheet material. The results of the tests show that certain combinations of aging time and temperature cause a marked increase in the yield strength and a small increase in the ultimate strength; these increases are accompanied by a very large decrease in elongation. A curve is presented that shows the maximum yield strengths that can be obtained by aging this material at various combinations of time and temperature" (p. 1).
- Effect of Carburetor-Mixture-Control and Supercharger Characteristics on Fuel Knock Under Simulated Sea-Level Flight Conditions
- Report presenting knock-limit data recorded for a current 100-octane-number aviation gasoline in a full-scale single-cylinder test engine. Inlet-air temperatures were the temperatures estimated from a consideration of the temperature increase through an aircraft-engine supercharger. The data indicate that the relation of the carburetor-mixture-control characteristics to the knock characteristics of the fuel is an important factor in determining knock-free operation.
- The Effect of Compressibility on the Growth of the Laminar Boundary Layer on Low-Drag Wings and Bodies
- The development of the laminar boundary layer in a compressible fluid is considered. Formulas are given for determining the boundary-layer thickness and the ratio of the boundary-layer Reynolds number to the body Reynolds number for airfoils and bodies of revolution. It is shown that the effect of compressibility will profoundly alter the Reynolds number corresponding to the upper limit of the range of the low-drag coefficients.
- The effect of compressibility on two-dimensional tunnel-wall interference for a symmetrical airfoil
- Summary: The effective change in the velocity of flow past a wing section, caused by the presence of wind-tunnel walls, is known for potential flow. This theory is extended by investigation of the two-dimensional compressible flow past a thin Rankine Oval. It is shown that for a symmetrical section at zero angle of attack the velocity increment due to the tunnel walls in the incompressible case must be multiplied by the factor 1/1-M^2 to take account of compressibility effects. The Mach number, M, corresponds to conditions in the wind-tunnel test section with the model removed (p. 1.).
- The effect of dead rise upon the high-angle porpoising characteristics of two planing surfaces in tandem
- Report presenting porpoising tests of three rudimentary models composed of two V-bottom planing surfaces in tandem and fitted with a tail plane. The upper and lower branches of the upper trim limit of stability were determined for three angles of dead rise and two depths of step.
- Effect of Exhaust Back Pressure on Engine Power
- Report presenting data on the effect of exhaust back pressure on engine power for 14 aircraft engines. The data showed that the effect of exhaust back pressure on engine power varies with engine speed, range of back pressure and manifold pressure involved, and engine type. The only method of accurately determining the effect of back pressure on engine power than can currently be recommended is to test the specific engine type at the engine speed for which data are desired.
- The Effect of Fast Fission on k
- The importance of fast neutron fission (i.e., fission caused by neutrons before being slowed down) was recognized by Szilard, and calculations similar to the present one have already been carried out by him, Feld, Ashkin, Wheeler, Wigner and others. The purpose of the present paper is to give a general formula for the contribution of fast fission to the multiplication constant, which will include all the cases already considered and will be applicable to more complicated geometries than those considered by the previous writers.
- Effect of Fillers and of Mixing Procedure on the Strength of Plastic Materials
- Note presenting a study to prepare a series of molding powders with the use of a given plastic and given fillers in varying proportions and to determine the effect of the differences in composition of the molding powders on certain physical properties of standard test pieces molded from them.
- The effect of inlet-valve design, size, and lift on the air capacity and output of a four-stroke engine
- Report presenting a series of performance tests made with a CFR engine at constant inlet pressure and temperature and constant exhaust pressure. Special cylinder heads with different sizes and designs of inlet valve and port were used.
- Effect of Length-Beam Ration on Resistance and Spray of Three Models of Flying-Boat Hulls
- Report presenting an investigation of the effect of changes in the length-beam ratio of flying-boat hulls on resistance and spray. A family of three models of hulls of different length-beam ratios was used and, in order to maintain comparable hull sizes, the plan-form areas of the hulls were made approximately equal by keeping equal products of length and beam. Results regarding resistance, spray, and take-off performance are provided.