Technical report describing a gasometrical method for the determination of H2 in extruded U rods.

Report issued by the U.S. Bureau of Mines discussing the annual report over the research and technology of coal during 1943. The report describes mining methods, and properties of coal. This report includes tables, illustrations, photographs, and a map.

Monthly report from the Greater New York Region to the National Board of Directors for the American Women's Voluntary Services discussing their news and activities including new blood donors and nurses and increased membership in the motor transport service.

Monthly report from the Public Relations Department to the National Board of Directors for the American Women's Voluntary Services discussing their news and activities including updates on their charity and publicity campaigns. Also listed are radio releases for the month.

Monthly report from the Public Relations Department to the National Board of Directors for the American Women's Voluntary Services discussing their news and activities including a summary of the last four meetings of the executive committee from the board of directors. A survey was sent out to see how the organization could improve in the post-war era.

Results of type II UF/sub 6/ centrifuge operation are presented. Data from this type operation in a single unit are useful in predicting the operation of a number of centrifuges in cascade. (J.R.D.)

Some methods for calculating the k requirements of various shaped piles are indicated, with particular reference to the shape of the tank in the homogeneous plant.

Report issued by the U.S. Bureau of Mines discussing coal mine fires and explosions during the fiscal year of 1943. Causes of the fires and explosions are presented, as well as the number of fatalities from each. This report includes tables, and illustrations.

Report discusses an investigation that was conducted to compare the strength and tightness of machine-countersunk flush-riveted joints assembled with NACA flush rivets and a type of commercial flush rivet. A comparison was also generated between the strength and tightness of counterpunched flush-riveted joints assembled with the same types of rivet. NACA's flush-riveted joints tended to be stronger and tighter than the commercial joints.

Report presenting the calculated performance of four-, six-, and eight-blade single-rotating propellers compared with experimental results for blade angles ranging from 25 to 65 degrees. The data were obtained on propellers mounted in front of a streamline body with a spinner housing the hub.

Report presenting compression testing on several series of flat panels with Z-section stiffeners with varying relative dimensions. The data presented show the effect of dimension ratio on the buckling stress for the sheet and on average stress at maximum load.

The bomb reaction slag produced at the ElectroMetallurgical X metal plant is at present divided into rich C-1 slag and lean C-2 slag by merely screening through a 4 mesh wire screen, the "on 4 mesh" material becomes the C-1 slag and the "thru 4 mesh" material becomes the C-2 slag. In the experiments covered by this report it was found that the concentration of the lean C-2 slag could be facilitated by the use of a 20 mesh screen for the slang separation in place of the 4 mesh screen, as the 20 mesh screen removed troublesome, small, hard lumps which passed the 4 mesh screen. Furthermore, it was found that the additional small lumps removed by the 20 mesh screen were just as rich in X metal as the larger lumps which make up the bulk of C-1 slag.

In this report a method is presented for the calculation of the profile drag of airfoil sections. The method requlres only a knowledge of the theoretical velocity distribution and can be applied readily once this dlstribution is ascertained. Comparison of calculated and experimental drag characteristics for several airfoils shows a satisfactory agreement. Sample calculatlons are included.

Report presenting an equation based on simple blade-element theory and the assumption of a fixed wake pattern is derived and fitted to available data to show the first-order relation between the parameters of propeller operation and intensity of wake-excited periodic force acting on the blades of a pusher propeller. The derived equation indicates that the effect of power coefficient on the intensity of the wake-excited periodic force is small. Limited data also indicates that the wake-excited vibratory stress in a propeller increases with the drag of the body producing the wake.

Report presenting corrections to the velocities near a cowling-flap tip in order to determine jet-boundary corrections to cowling-flap-outlet pressures. The presence of the low-energy air leaving the flap opening was taken into account by so shaping the nacelle model that its outer surface represented the stream surface leaving the flap tip. Copper was found unsatisfactory for use as electrode material.

Report presenting a tabular method for determining the span load distribution at high Mach numbers by utilizing high-speed airfoil section data. This method, which is also called the generalized method, is an easily applied process of successive approximations by which a general application of the lifting-line theory may be used to determine the span load distribution for wings composed of sections with arbitrary lift curves. An example is provided to show how the method is used.

Report presenting an investigation of the shape of stress-strain curve for a material, especially when the material is subjected to compression, which may cause materials to become unstable at stresses beyond the elastic range. The ratio of stresses to effective modulus is explored in equation form.

Results are presented for tests of two wings, an NACA 230-series wing and a highly-cambered NACA 66-series wing on a twin-engine pursuit airplane. Auxiliary control flaps were tested in combinations with each wing. Data showing comparison of high-speed aerodynamic characteristics of the model when equipped with each wing, the effect of the auxiliary control flaps on aerodynamic characteristics, and elevator effectiveness for the model with the 66-series wing are presented. High-speed aerodynamic characteristics of the model were improved with the 66-series wing.

Report presenting measurements in the full-scale tunnel of the pressure distribution over the horizontal tail surface of a typical pursuit airplane in order to determine the effects of propeller operation and angle of yaw on the tail load distribution. Most of the tests were made with the propeller operating to simulate climb conditions, high-speed dives, and pull-ups to various normal accelerations for a range of angles of yaw. Results regarding chordwise pressure distributions, spanwise distributions of normal-force coefficient, airflow measurements, and tail-load asymmetry are provided.

The temperature coefficient of eta has been measured with the thermal column of the Argonne pile using uranium foils of different isotopic ratios. The temperature change was effected by filtering neutrons through silver. The measured fractional change per degree centigrade is [formula].

Report presenting an extension of tables of stiffness and carry-over factor to include the stiffness of a member with the far end subjected to a moment equal and opposite to the moment applied at the near end. The formulas used in calculation to determine the values are also provided.

Abstract: "Photographic plates have been used to measure the energy of neutrons from the fission of 25. The spectrum as inferred from the ranges of 850 protons recoiling in the forward direction shows a very wide maximum at ~1.5 Mev with an exponentially decreasing high energy tail which extends beyond 7 Mev. The minimum energy neutrons recorded were ~700 kv. If the spectrum is extrapolated to zero, one finds that this average neutron energy is about 1.85 Mev. The stopping power of the plates was calibrated by the use of monochromatic neutrons from the Li-7(pn) Be-7 reaction and the d-d reaction."

Report presenting testing made on a Wright 1820-G single-cylinder engine to determine the effect of operating variables and the effect of shape and size of the exhaust stack on the visibility of exhaust gases for individual-stack installations. Flame damping was improved by decrease in nozzle-exit area, increase in stack length, and reduction in hydraulic diameter of the exhaust jets. Results regarding the characteristics of exhaust flames and damping of exhaust flames are provided.

Report presenting an investigation of the effectiveness of suction slots as a means of extending the laminar boundary layer in flight at high Reynolds numbers on an NACA 35-215 airfoil. The results showed that, with a slot spacing of about 5 percent of the chord, the laminar boundary layer could be maintained to or slightly beyond 45 percent of the chord.