This note describes some results of the study of single pion production in π⁻-p interactions at 4.65 Bev/c, using the BNL 20" Hydrogen Bubble Chamber. It is well known that the observability of some of the particle resonances (e.g. 33 Isobar and η) varies markedly with the energy of the incident particle. The ρ meson has been observed in π⁻-p interactions at 1.25 Bev/c and 1.9 Bev/c incident pion energies. Evidence will be shown that this resonance persists with the much higher incident pion energy used in the present experiment.

The absorption bands induced in α-Al2O3 by gamma and reactor irradiation have been studied. The slight coloration due to γ-rays saturates. Bands specific to reactor irradiation have been found and their growth studied.

FLOSS III is a third-generation version of a digital computer program which solves a one-dimensional difference representation of the momentum, energy, continuity, and state equations for turbulent, compressible gas flow in equivalent hydraulic channels. Extensive use of this program has been employed in the design and performance analyses of Pluto-type nuclear heat exchangers, and in the specific case of the Tory II-A test series, agreement was obtained to better than 5% for all experimentally measured parameters. The NOMAC and DASH-N programs combine the effects of up to thirty varieties of channels with the dependent boundary conditions imposed by a common inlet diffuser and exit nozzle. The resulting calculations yield performance information for blow-down facility and ramjet flight condition application of the heat exchanger.

Three proprietary high strength, low alloy steels and a high strength alloy steel were welded without a pre or post heat treatment with low hydrogen, iron powder coated electrodes of appropriate physical properties. Tensile and bend tests performed upon sample weldments indicated that they exhibited properties very similar to those for the base plate and that there were no indications of brittleness, notch sensitivity, underbead cracking, lack of fusion, hot cracking, undercutting, or crater cracking.

This report deals with the structural and lithologic features within and adjacent to the San Juan mineral belt and the relation of these features to the ore deposits.

A report which covers progress on the testing of the General Engineering and Consulting Laboratory Turbine Pump No. 1 from June 16, 1948, to July 31, 1948.

Abstract: "Formulas are derived for the trajectory of a charged particle in a magnetic field which is a linear function of time. Graphs of certain functions are presented, by means of which a trajectory with given initial position and velocity may be plotted."

Report issued by the Oak Ridge National Laboratory discussing quarterly progress made by the Homogeneous Reactor Program. It includes descriptions of progress and studies conducted during the report period, with tables, illustrations, and photographs.

Results of an investigation carried on for the following purposes: (1) To determine the relative life of filaments when operated at low emission (low temperatures) as compared to those operated at high emission values. (2) To determine the nature of the dependence of life upon the initial diameter of the filament. (3) To determine the effect of varying concentrations of water vapor and air upon the life of the filaments. (4) To determine the relative life characteristics of tantalum as compared to tungsten.

Startup and initial operation of the APPR-1 and summary of the results of the test program on the reactor.

Report presenting a theoretical method for calculating heat transfer in the laminar boundary layer on yawed infinite cylinders in compressible flow. The method can be applied to a cylinder of arbitrary cross section and arbitrary chordwise wall-temperature distribution. The variation in local heat transfer around the surface of the cylinder was found to have little functional dependence on yaw angle or wall temperature.

Report presenting testing of two 2024-T3 aluminum-alloy multiweb wing structures (MW-2 and MW-3), similar to airplane or missile wings, at a Mach number of 2 under simulated supersonic flight conditions. Results regarding experimentally determined test conditions, model temperatures, strain-gage results, and model failures are provided. The report indicates that much of the stress data does not agree with expected results, but there is too much uncertainty regarding the reduction of strain data that no conclusions can be made concerning the results.

"Some of the considerations involved in the design of aircraft fuel tanks for liquid hydrogen are discussed herein. Several of the physical properties of metals and thermal insulators in the temperature range from ambient to liquid-hydrogen temperatures are assembled. Calculations based on these properties indicate that it is possible to build a large-size liquid-hydrogen fuel tank which (1) will weigh less then 15 percent of the fuel weight, (2) will have a hydrogen vaporization rate less than 30 percent of the cruise fuel-flow rate, and (3) can be held in a stand-by condition and readied for flight in a short time" (p. 1).

Memorandum presenting an investigation of a model with a ramp that produced an oblique shock wave in front of an annular duct inlet, which was tested at Mach numbers between 1.36 and 2.01 to determine the effect of reducing the entrance Mach number on the total-pressure recovery after diffusion. The results showed that the maximum total-pressure recovery of the model investigated was considerably improved through the addition of a ramp.

Report presenting a wind-tunnel investigation on 3.5-percent-thick symmetrical double-wedge delta wings to determine the effects of thickness distribution on lift, drag, and pitching moment. Six maximum-thickness positions were tested on three basic wings at different Mach numbers and Reynolds numbers. Results regarding lift, drag, the lift-drag ratio, and the center of pressure are provided.

"Fuel injected into a spherical bomb filled with air at a desired density and temperature could be ignited with a spark a few thousandths of a second after injection, an interval comparable with the ignition lag in fuel-injection engines. The effect of several variables on the extent and rate of combustion was investigated: time intervals between injection and ignition of fuel of 0.003 to 0.06 second and one of 5 minutes; initial air temperatures of 100 degrees C. to 250 degrees C.; initial air densities equivalent to 5, 10, and 15 absolute atmospheres pressure at 100 degrees C.; and air-fuel ratios of 5 to 25" (p. 107).

From Summary: "Directly comparable drag measurements have been made of an airfoil with a conventional rectangular plan form and an airfoil with a sweptback plan form mounted on freely falling bodies. Both airfoils had NACA 65-009 sections and were identical in span, frontal area, and chord perpendicular to the leading edge. The sweptback plan form incorporated a sweepback angle of 45 degrees. The data obtained have been used to establish the relation between the airfoil drag coefficients and the free-stream Mach number over a range of Mach numbers from 0.90 to 1.27. The results of the measurements indicate that the drag of the sweptback plan form is less than 0.3 that of the rectangular plan form at a Mach number of 1.00 and is less than 0.4 that at a Mach number of 1.20."

"Investigations have been conducted to determine by means of total-pressure surveys the boundaries of single and twin jets discharging through convergent nozzles into quiescent air. The jet boundaries for the region from the nozzle outlets to a station 6 nozzle diameters downstream are presented for nozzle pressure ratios ranging from 2.5 t o 16.0 and for twin-Jet nozzle center-line spacings ranging from 1.42 to 2.50 nozzle diameters. The effects of these parameters on the interaction of twin Jets are discussed" (p. 1).

Results of previous model ditching tests of the Lockheed Constellation airplane are reported. Further model tests have been made to determine the probable ditching characteristics and the proper ditching technique for the airplane with the Speedpak attached. This paper presents the results of these tests. Design information was furnished by the Lockheed Aircraft Corporation. A three-vies drawing of the airplane with the Speedpak attached is shown. The tests were made in calm water at the Langley tank no.2 monorail.

A model of a Consolidated Vultee Aircraft Corporation Skate 7 sea-plane was tested in Langley tank no. 2. Resistance data, spray photographs, and underwater photographs are given in this report without discussion.

Annular blade-element data obtained primarily from single-stage compressor installations are correlated over a range of inlet Mach numbers and cascade geometry. The correlation curves are presented in such a manner that they are related directly to the low-speed two-dimensional-cascade data of part VI of this series. Thus, the data serve as both an extension and a verification of the two-dimensional-cascade data. In addition, the correlation results are applied to compressor design.

Memorandum presenting low-speed wind-tunnel tests made of flat-plate wings with an aspect ratio of 2.0 and their leading edges swept back 63.4 degrees. Both plain and split flaps of several plan forms were investigated to provide qualitative information as to the relative merits of these flaps. The constant-chord flap was found to be the most effective and a skewed wing-tip flap the least effective.

Report discussing an investigation to determine the effect of sweepback on the static and rolling stability derivatives of a series of wings with a taper ratio of 0.6 and an aspect ratio of 4. The influence on the straight-flow characteristics, rolling-flow characteristics, and aileron characteristics are provided.

Memorandum presenting an investigation to determine the static directional stability of a fuselage typical of tandem helicopters. The model consisted of a body with an elliptical cross section, a rear rotor pylon which was faired to form a large vertical tail with a very thick airfoil section, and a small horizontal tail mounted at about the midpoint of the height of the vertical tail. Results regarding the stability of the original model, the causes of low directional stability, and tests of some practical modifications of increasing directional stability are provided.