The following report is the first semi-annual report of a literature survey designed to investigate the uses and technology of radioisotopes in the countries of the world from 1955 to the present. This survey includes two phases: 1) involves the direct comparison of radioisotopic work in all fields in various countries as demonstrated at international conferences. 2) involves a more detailed examination and evaluation of the individual fields of interest selected previously (Phase II is also expected to comprise the bulk of the remainder of this investigation).

From Abstract: "The heat treatment and mechanical properties of four zirconium alloys...were investigated. Tensile, hardness, Jominy end-quench, and metallographic data constitute the basis for much of the report. Other data reported include the results of high-temperature creep, tensile, hardness, cold rolling, thermal-cycling, and dynamic-modulus tests." A connection is made between the behavior of these four alloys and more alloys in the zirconium-uranium system.

From Introduction: "The purpose of the flight investigation described herein was as a "proof" check of the system and to determine what effect several variables which could not be practicably simulated would have on the operation."

Report presenting the experimental values of damping in roll of the Bell X-1A airplane and its components at 5 Mach numbers at zero angle of attack. The wing was found to be the predominant contributor to the damping in roll throughout the range of Mach numbers, but the contributions of other airplane components were significant in the range of 2.22 to 2.41.

Memorandum presenting an investigation to determine the feasibility of increasing the specific weight flow of a transonic axial-flow compressor inlet stage by decreasing the hub-tip ratio. The current phase of the investigation was conducted to determine the blade-element and the overall performance of the complete stage. Results regarding the overall performance, blade-element performance, and stator-blade-element performance are provided.

Memorandum presenting an experimental investigation conducted at Mach numbers 1.5, 1.8, and 2.0 to determine the effects of several throat boundary-layer bleed configurations on the performance of a 25 degree half-conical side-inlet system. The effects of several flush-slot configurations and a porous-surface bleed were determined over ranges of angle of attack and bleed-duct and main-duct mass flow.

Memorandum presenting an investigation of aileron effectiveness and dihedral effect for a wing-body combination with a variable-incidence triangular wing with modified half-delta controls at the wing tips. The tests were conducted at a Mach number of 1.52 at a Reynolds number of 0.82 million. The experimental value of aileron effectiveness at 0 degrees angle of attack was approximately 78 percent of the value predicted by linear theory, and the effectiveness decreased with increasing wing angle of attack.

Report presenting a wind-tunnel investigation of bomb-release problems by measuring static forces for computation of bomb drop paths. Forces and moments were measured on bombs of three fineness ratios and on a swept-wing fighter-bomber configuration for several positions of the bomb under an open bomb bay. Results regarding contour paths and drop-path calculations are provided.

Heat-transfer data from supersonic wind-tunnel tests of a heated 20 degree cone are compared with theoretical results obtained by the method for determining the convective heat transfer in laminar boundary layers in a compressible fluid developed by Hantzche and Wendt and with the method presented in NACA TN No. 1300. The experimental data are also compared with the results obtained by Eber at the Kochel Laboratory in Germany and it is found that Eber's results correspond to those obtained with a turbulent boundary layer on the cone. The results provide a qualitative verification of the effect of heat transfer on laminar boundary-layer stability that has been predicted theoretically by Lees in NACA TN No. 1360.

An investigation was conducted on an axial-flow-compressor type turbojet engine in the NACA Lewis altitude wind tunnel to determine the operational characteristics of several ignition systems, cross-fire tube configurations and fuel systems over a range of simulated flight conditions. The opposite-polarity-type spark plug provided the most satisfactory ignition. Increasing the cross-fire-tube diameter improved intercombustor flame propagation. At high windmilling speeds, accelerations to approximately 6200 rpm could be made at a preset constant throttle position. The use of a variable-area nozzle reduced acceleration time.

Report presenting an investigation of a large-scale triangular wing with 60 degrees of leading-edge sweep and with 10-percent-thick circular-arc airfoil sections parallel to the plane of symmetry was made in the full-scale tunnel to determine the effects of wing leading-edge modifications and several outboard fin arrangements on the low-speed static stability characteristics. Results regarding static longitudinal stability characteristics and static lateral stability characteristics are provided.

Report presenting a small-scale investigation of two semispan wings with the same plan form in the high-speed 7- by 10-foot tunnel over a range of Mach numbers to determine the effects of twist and camber on the aerodynamic characteristics of a 60 degrees 42' sweptback wing of aspect ratio 1.94. Lift, drag, pitching moment, and root bending moment were obtained for the two wings investigated.

Report presenting an investigation of the principal variables affecting the excitation of a propeller for vibration at a frequency of twice propeller speed using a conventional propeller with solid aluminum-alloy blades operating in the wake of a wing. The drag of the wing and spacing between the flap trailing edge and propeller plane were all adjustable. Results regarding wing drag data, vibratory stresses, damping, and theoretical considerations of wake excited blade stresses are provided.

"A qualitative investigation of the low-speed directional behavior of a swept planing-tail hull was made in the Langley tank no. 2 in still water and still air with the use of a free self-propelled model. The configuration was directionally unstable over a range of low speed. It was, however, directionally controllable at all speeds by use of the rudder and elevator. Several modifications that were investigated did not improve the controllability" (p. 1).

"Aileron effectiveness and dihedral effect were investigated for a wing-body combination having a variable-incidence triangular wing with modified half-delta controls at the wing tips. The tests were conducted at a Mach number of 1.52 at a Reynolds number of 0.82 million. At the Mach number of the tests, the Mach cone from the wing apex was almost coincident with the wing leading edge" (p. 1).

Report presenting an investigation in the 4- by 4-foot supersonic pressure tunnel at Mach number 1.60 to determine the effects of sweep and thickness on the longitudinal characteristics of a series of wing-body combinations with cambered wings with an aspect ratio of 3.5 and taper ratio of 0.2. The results show the effects of sweep, thickness, and the horizontal canard surface on the lift, drag, and pitching-moment coefficients and lift-drag ratios. The lift-curve slope, aerodynamic-center locations, maximum lift-drag ratios, lift coefficients for maximum lift-drag ratio, and drag-rise factor are presented.

"A procedure is presented for obtaining the pressure distribution on an arbitrary airfoil section in cascade in a two-dimensional, incompressible, and nonviscous flow. The method considers directly the influence on a given airfoil of the rest of the cascade and evaluates this interference by an iterative process, which appeared to converge rapidly in the cases tried (about unit solidity, stagger angles of 0 degree and 45 degrees). Two variations of the basic interference calculations are described" (p. 1).

Report presenting an investigation of the effects of changing indentation design Mach number on the aerodynamic characteristics of a 45 degree sweptback-wing-body combination designed for high performance at a range of Mach numbers. Theoretical results of zero-lift wave drag for the wing-body combination agreed well with the experimental data. Results regarding the bodies, systematic series of wing-body combinations, -2 degree angle of incidence, M = 1.4 revised body, and transition are presented.

Memorandum presenting an investigation to determine the altitude performance characteristics of the YJ73-GE-3 turbojet engine in an altitude chamber. The component performance was determined at two positions of the inlet guide vanes over a range of engine speeds, exhaust-nozzle areas, and flight conditions. Results regarding compressor performance, combustor performance, turbine performance, and altitude performance of components at rated conditions are provided.

Report presenting an investigation of the effect of inlet-air baffles on the rotating stall, rotor-blade vibratory stress, and performance characteristics of a compressor in an axial-flow turbojet engine. Two baffles were tested, an inside-diameter baffle extending radially outward from the hub, and an outside-diameter baffle extending radially inward from the outer casing.

Memorandum presenting an investigation to determine the off-design characteristics of a counterrotating turbine component in a two-spool turbojet engine. The results indicated that the inner turbine was conventional with respect to off-design characteristics when considered as a separate unit. Results regarding the performance with and without the outer-turbine stator are provided.

From preface: The following bibliography on high pressure-high temperature, and high pressure, is the result of an investigation into the equipment and experimental technique needed to increase the density of powdered compounds, especially those compounds which possess a high vapor pressure of hydrogen at moderate temperature and pressure.

The following report calculates pile reactivity changes that result from different pile loadings where it is desirable to have available values of (flux)2 d(volume) for various flat zone radii. This information was found for a cylindrical pile having circular flat zones and an effective radius of 598 cm., by integrating over a cross sectional volume of one cm. thickness.

A report regarding a survey of the condition of wells and springs in the Rio Blanco County, in N.W. Colorado.