A comparatively rapid method is presented for determining theoretically the bending stresses of helicopter rotor blades in forward flight. The method is based on the analysis of the properties of a vibrating beam, and its uniqueness lies in the simple solution of the differential equation which governs the motion of the bent blades.

Report presenting charts to provide a convenient means for obtaining the derivatives of rotor resultant force, rotor pitching amount about the helicopter center of gravity, and rotor torque with respect to rotor angle of attack, forward speed, rotor speed, and collective pitch.

Technical report covering chemistry of source, fissionable, and structural elements, nuclear chemistry, radio-organic chemistry, chemistry of separations processes, chemical physics, radiation chemistry, and instrumentation at the Oak Ridge National Laboratory for the period ending September 30, 1950. [From Abstract]

Jet boundary corrections for partly open and partly closed elliptical wind tunnels for the cases of one and two solid wall segments are presented. Also presented are the combinations of model span and extent of the solid portion of the tunnel wall for which the average correction factor is zero.

The Euler equations for the rotation of a solid body are applied to the problem of the motion of ultracentrifuges. Particular attention is paid to the problem of the passage of an ultracentrifuge rotor through the critical velocity. The factors that affect the passage of rotors through the critical point are stressed.

Report issued by the U.S. Bureau of Mines investigating the well patterns and spacing of the Paola shoestring reservoir in Kansas. Several methods of field tests are presented. The report includes illustrations and tables.

From Summary: "As part of a study of means of airspeed measurement at transonic speeds the use of static orifices located ahead of the wing tip has been investigated for possible application to service or research airspeed installations. The local static pressure and local Mach number have been measured at a distance of 1 tip chord ahead of the wing tip of a model of a swept-wing fighter airplane at true Mach numbers between 0.7 and 1.08 by the NACA wing-flow method. All measurements were made at or near zero lift. The local Mach number was found to be essentially equal to the true Mach numbers less than about 0.90."

Report presenting information on the axial-load fatigue behavior of unnotched specimens of 24S-T3 and 75S-T6 aluminum alloys and normalized SAE 4130 steel. The primary objectives of the investigation were to determine fatigue strengths and measurements of damage due to stress level are provided. Results regarding static strength tests, fatigue strength tests, fatigue damage tests, and results at high and low speeds are provided.

Note presenting an investigation to determine the static-thrust performance of a coaxial helicopter rotor with blades tapered both in plan form and thickness ratio in the full-scale tunnel. Tests of the coaxial-rotor and single-rotor configurations were made for a range of blade-pitch setting and for a range of tip speed up to 500 feet per second. Results regarding the hovering performance, effect of variation in directional control, and variation of rotor figure of merit with ratio of thrust coefficient are provided.

Note presenting a general steady through-flow theory of nonviscous fluid in turbomachines of arbitrary hub- and casing-wall shapes with subsonic or supersonic velocity. The theory is applicable to both direct and inverse problems and is derived primarily for use in turbomachines with thin blades of high solidity with a simple approximate correction factor for blade-thickness effect.

Note presenting a basic theory of generalized linearized supersonic conical flow for both inside and outside the Mach cone, which was developed and applied to several specific problems including unsteady-flow conditions. A triangular lifting wing in pitching and rolling with both subsonic and supersonic leading edges was investigated and pressure coefficients were obtained.

Report discussing the identification of hydrothermal uranothorite from fluorite breccias in Colorado and its comparison/contrasting with other uranothorites and thorites. A description of thorium halos in fluorite is given.

Abstract: Summaries of the geology and mineral deposits, and appraisals of the uranium possibilities of the various regions of Alaska are presented in this report.

Monthly report of the U.S. Geological Survey's trace element investigations including an outline of field work, laboratory work, and staff activities that have been completed or are in process.

Report presenting a linearized solution for the problem of plastic deformation of a thin plate with a circular hole in the strain-hardening range. It is based on the deformation theory of plasticity for finite strains.

"Liquid-water content, droplet size, and temperature data measured during 22 flights in predominately stratiform clouds through the 1948-49 and the 1949-50 winters are presented. Several icing encounters were of greater severity than those previously measured over the same geographical area, but were within the limits of similar measurements obtained over different terrain within the United States. An analysis of meteorological conditions existing during the 74 flights conducted for four winters indicated an inverse relation of liquid-water concentration to maximum horizontal extent of icing clouds" (p. 1).

Note presenting a method for the determination of the spanwise load distribution of a flexible swept wing at subsonic speeds. The method is based on a relaxation approach using aerodynamic loadings obtained from previously published work based on Weissinger's simplified lifting-surface theory together with simple beam theory.

A tentative nickel-plutonium constitutional diagram was based on data obtained by thermal analysis, metallography, and x-ray-diffraction techniques. The systema is a complex one with the following important features. Nickel is soluble in epsilon plutonium, extending the epsilon field to 4.3 at.% nickel at 465 deg C. Nickel and plutonium form six intermetallic compounds, PuNi, EnNi/sub 2/, PuNi/sub 3/, PuNi/sub 4/, PuNi/sub 5/, and PuNi/sub 9/. The compound PuNi/ sub 5/ forms congruently from the melt at approximately l300 deg C, whereas the other compounds form peritectoidally. The extended epsilon field terminates in a eutectoid reaction at 415 deg C and l.5 at.% nickel. Epsilon plutonium and the compound PuNi form a eutectic system at 465 deg C with a eutectic composition of l2.5 at,% nickel. Nickel and the compound PuNi/sub 9/ form a eutectic system at l2l0 deg C with a eutectic composition of 92 at.% nickel. Plutonium forms a limited solid solution with nickel.

A report regarding plans for the Geological Survey's investigations of uranium in pre-Morrison formations in southern Utah, Northern Arizona, and Northwestern New Mexico.

Report presenting an experimental investigation of pyramidal, wedge-like bodies as devices for delaying separation of a turbulent boundary layer. Within certain limits, effective boundary-layer control was obtainable with wedges of different geometry, but the drag of the wedges was high, making it desirable to keep their size to a minimum. Greater maximum lift was obtainable by placing the wedges well forward along the chord and by allowing open spaces between adjacent wedges.

A preliminary reserve statement regarding Reserve Blocks B and C, as well as Mineral Channels 10 and 12 of the Outlaw Mesa, located in Mesa County, Colorado.

A preliminary reserve statement regarding Reserve Block A, of the Long Park Vicinity, located in Montrose County, Colorado.

A preliminary reserve statement of Reserve Block B, of the Long Park Vicinity, located in Montrose County, Colorado.

This report discusses the need for considering a wide variation in certain of the basic flutter parameters in conducting a flutter analysis. Conclusions are drawn stating that design charts or simple rules may be misleading. Due to inherent difficulties, dynamic model testing may also yield misleading results. The general flutter equations and various methods of solution are discussed. Of particular interest, curves are presented showing computational effort plotted against a number of degrees of freedom used in a flutter analysis.