Report regarding ion chamber measurements made of the external environmental radiation in various location in the United States during the summer of 1957.

Memorandum presenting a supersonic wind-tunnel investigation of the origin and distribution of store interference in the 4- by 4-foot supersonic pressure tunnel at Mach number 1.6 in which separate forces on a store, a fuselage, a swept wing, and a swept-wing-fuselage combination were measured. The store was separately sting-mounted on its own six-component internal balance and was traversed through a wide systematic range of spanwise, chordwise, and vertical positions.

"Instrument-flying trials have been conducted in a single-rotor helicopter, the maneuver stability of which could be changed from satisfactory to unsatisfactory. The results indicated that existing longitudinal flying-qualities requirements based on contact flight were adequate for instrument flight at speeds above that for minimum power. However, lateral-directional problems were encountered at low speeds and during precision maneuvers" (p. 1).

"Pressure-distribution and force tests of a circular cylinder have been made in the Langley 11-inch hypersonic tunnel at a Mach number of 6.86, a Reynolds number of 129,000 based on diameter, and angles of attack up to 90 degrees. The results are compared with the hypersonic approximation of Grimminger, Williams, and Young and with a simple modification of the Newtonian flow theory. The comparison of experimental results shows that either theory gives adequate general aerodynamic characteristics but that the modified Newtonian theory gives a more accurate prediction of the pressure distribution" (p. 1).

Report presenting an investigation of the effects of suction through a porous leading-edge surface in the 19-foot pressure tunnel on a wing with 37 degrees of sweepback of the leading edge, an aspect ratio of 6, taper ratio of 0.5, and NACA 64(sub 1)-212 airfoil sections normal to the 27-percent-chord line. Results regarding the wing without flaps, wing with trailing-edge flaps, and power requirements for porous-leading-edge suction are provided.

A preliminary investigation was conducted to determine the combustion characteristics of a fuel composed of 50 percent pentaborane and 50 percent JP-4 (MIL-F-5624A) by weight in a turbojet combustor. A combustor designed to fit the housing of a J33-A-23 turbojet engine was selected for convenience. The fuel was evaluated at two engine conditions simulating altitudes of 40,000 and 57,000 feet, an engine speed of 85 percent of rated rpm, and a flight Mach number of 0.6. The pentaborane blend was initially evaluated in combustors developed for pure pentaborane and diborane reported in NACA RM E53B18 and RM E52L15. The performance of the blend was unsatisfactory in these combustors. A new combustor was then developed which provided combustor efficiencies measured from 91 to 101 percent as compared with efficiencies of 92 to 94 percent previously obtained for pentaborane at comparable conditions. Additional refinements of design details are needed to obtain lower oxide deposits and a more uniform outlet temperature profile; however, the combustor is believed to incorporate some of the design principles required to obtain satisfactory over-all performance with the fuel blend investigated.

From Summary: "An investigation was conducted in the 8-by-6 foot supersonic wind tunnel on the effect of exhaust-gas temperatures on the external and internal characteristics of a convergent-divergent nozzle having an area expansion ratio of 1.83. Data were obtained over a pressure-ratio range from 1 to 20 at free-stream Mach numbers of 1.6 and 2.0 for exhaust temperatures of 860 degrees, 1650 degrees, and 2000 degrees R. Results of this investigation indicated that generally both the internal and external performance characteristics were only slightly affected by a large change in jet temperature. The small differences in performance which did occur were predicted satisfactorily from theoretical considerations."

From Summary: "An experimental investigation was made to determine the feasibility of using hollow turbine blades in engines designed for short service life. Airfoils were fabricated from sheet material and techniques of welding and brazing attachment were investigated. The airfoils were not intended to be cooled. A principal objective was the reduction of strategic material requirements primarily as a function of direct weight reduction."

Report presenting measurements of the local flow angles near the fuselages of a triangular-wing wind-tunnel model and an F-86A-5 airplane in flight using airflow detectors on the fuselages. A comparison of the measured and predicted flow angles is provided. Results indicated that the accuracy of the predicted indicated angles of attack was not sufficient to eliminate the necessity of a flight calibration of a detector mounted on a fuselage.

Flow-visualization studies, using smoke, were made of the secondary flows in rectangular bends, tandem cascades, and high-turning configurations. The roll-up of the wall boundary layer of a rectangular bend forms a passage vortex near the suction surface similar to that previously observed for cascades. The vortex so formed then shifts out into the main stream. Because of leading-edge effects, the boundary-layer flows in bends were found to be sufficiently different from the flows in blade rows to make direct application of bend results to blade rows inadvisable.

Report presenting an analysis of results obtained from a transonic wind-tunnel investigation of two bodies of revolution with the same nose shape but two different shapes of afterbody. Results regarding pressure distribution, normal-force characteristics, pitching-moment and center-of-pressure characteristics, and detailed load characteristics are provided.

Report presenting an evaluation of convective heat-transfer coefficients from skin temperatures measured along the body of a research model designated NACA RM-10. Heat-transfer data is presented for a range of Mach and Reynolds numbers based on the axial distance from the nose to the point at which the temperature measurements were made. Results regarding the recovery factor, heat transfer, correlation with different aircraft models, and Reynolds analogy are provided.

Report presenting drag measurements on models of 20 isolated external stores and nacelles flown from the helium gun at a range of Mach numbers. Results regarding fineness-ratio and shape effects, drag correlation, and friction drag are provided. Generally, the shape variations among the various types of stores and nacelles had the expected effects on isolated body drag.

Report presenting an investigation of an axial-flow compressor rotor with an inlet hub-tip radius ratio of basically zero. Results regarding the radial distribution of total-pressure ratio and efficiency, measured pressure ratio at design speed, weight flow, and low-speed cascade data are provided.

Report presenting an investigation of the static lateral stability characteristics of a swept-wing fighter-type airplane with three vertical-tail configurations and two wing configurations at an altitude of 40,000 feet over a range of Mach numbers. Data was obtained in several conditions, including constant-heading sideslips and wings-level turns, aileron rolls, and abrupt rudder pulses. Results regarding the sideslip characteristics, lateral control, and control effectiveness derivatives are provided.

From Summary: "The manner in which imperfect space stabilization of the tracking radar influences the flight path stability of an automatic interceptor during the attack phase is illustrated by means of flight and analog-computer time histories. It is shown analytically that these effects may be interpreted in terms of a destabilizing airplane rate feedback which can be canceled by an additional compensatory feedback in the radar tracking loop."

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, John Ben Shepperd, regarding a legal question submitted for clarification: Legality of treating funds the United States Government is obligated to pay for student tuitions as being moneys collected for the purpose of determining public junior college appropriations.

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Will Wilson, regarding a legal question submitted for clarification: Effect of H. J. R. 32, which proposes a constitutional amendment to confer probate jurisdiction on County Courts at Law, Upon the Texas probate system.

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Will Wilson, regarding a legal question submitted for clarification; Can a county Commissioners' Court dispense with the use of voting machines in a special election after the Court has adapted the use of voting machines in the county under the provisions of Article 7.14, Section 3, Vernon's Civil Statues, Election Code?

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Will Wilson, regarding a legal question submitted for clarification: Whether a county mutual insurance company may write insurance on risks in states other than Texas?

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Will Wilson, regarding a legal question submitted for clarification: Constitutionality and Construction of Portions of the Adult Probation and Parole Law of 1957.

Letter opinion issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, John Ben Shepperd, regarding a legal question submitted for clarification: Constitutionality of House Concurrent Resolution 24 of 53rd Legislature that no statute of limitation shall bar the claim of Mr. R. E. Cowan against Jefferson County for the balance of his 1933 salary as District Clerk of Jefferson County.

Report on the principle of measuring the time-of-flight of neutrons, magnetic-core storage of detector pulses, how pulses are stored, current generator, storage cycle generator, and cathode ray oscillograph.

The SNAP Experimental Reactor (SER) is a small power reactor that is to be built and operated in the original SNAP-II critical facility. The reactor is described, and the hazards previously evaluated for the SNAP II critical faciity are reviewed.