During the course of a research problem involving hydrofluoric acid it became necessary to filter concentrated hydrofluoric solutions to remove various solid materials. The search for a suitable filter media finally led to the use of a commercially manufactured plastic material known as ``Sponge Teflon`` (polytetrafluoroethylone) which is produced by the DuPont Company. This material, which comes in 1/8 in. sheets, is used primarily as a gasket material in acid lines, and is impervious to all acids, including hydrofluorle acid.

Memorandum presenting an analysis of the two-dimensional, geared, trailing-edge flap-tab combination at supersonic speeds to determine if the combination could be used to reduce the hinge moments to extremely small values while retaining a large part of the lift effectiveness of a plain flap with the same ratio of flap chord to wing chord.

"The production-model 333-A-23 turbojet-engine compressor with a 17-blade impeller was operated at ambient and 0 F inlet temperatures and at inlet pressures of 14 and 5 inches mercury absolute for equivalent impeller speeds from 6000 to 12,750 rpm. The results of this investigation are compared with those of the 533-A-21 compressor. At the design equivalent speed of 11,750 rpm the maximum pressure ratio was 4.39" (p. 1).

An investigation of several ejector configurations to determine the ability to handle the air required for engine cooling. The results are limited to investigations of conical-type mixing-section ejectors at ratios of mixing-section minimum diameter to primary-jet-nozzle diameter using unheated air. Results regarding experimental data, generalization of experimental data, spacing for maximum weight-flow ratio, ejector thrust, ejector configurations for constant weight-flow ratio, and selection of ejector design are provided.

None

None

"The effects of propeller operation on the static longitudinal stability of single-engine tractor monoplanes are analyzed, and a simple method is presented for computing power-on pitching-moment curves for flap-retracted flight conditions. The methods evolved are based on the results of powered-model wind-tunnel investigations of 28 model configurations. Correlation curves are presented from which the effects of power on the downwash over the tail and the stabilizer effectiveness can be rapidly predicted" (p. 399).

"An investigation has been made in the Langley 16-foot high-speed tunnel to determine the propeller-section characteristics by measuring the pressure distribution on the airfoil sections of a rotating propeller. The pressures were measured at nine radial stations on an NACA 10-(3)(08)-03 design two-blade propeller. This paper presents the results of the pressure measurements in the form of normal-force and moment coefficients and covers a range of nominal angle of attack (simple blade element theory) from 0 degrees to 4 degrees for a section Mach number range of approximately 0.6 to 1.15 for the outboard stations and approximately 0.3 to 0.6 for inboard stations" (p. 1).

This document is a declassified July 1948 Progress Report on Process Research at Monsanto Chemical`s Mound facility. Areas discussed are: (1) treatment of hot solid wastes, and (2) treatment of hot liquid wastes. Chemical aspects of these processes are noted.

This memorandum discusses briefly and approximately the two extreme programs which could be followed in the production of Ta{sup 182}: the use of present available excess reactivity, and the use of a pile, continuing no U{sup 238}, expressly to produce Ta{sup 182}. Use of lesser amounts of enriched material would achieve lesser production rates. The cost in fissionable material per gram of active isotope would remain approximately the same.

This is the University of California, Radiation Laboratory progress report for June 15-July 15, 1948. It discusses the following: (1) 184-inch Cyclotron Program; (2) 60-inch Cyclotron Program; (3) Synchrotron Program; (4) Linear Accelerator Program; (5) Experimental Physics; (6) Theoretical Physics, (7) Isotope Separation Program; (8) Chemistry Departments; (9) Medical Physics; and (10) Health Physics and Chemistry.

Using an apparatus described in a preceeding paper the reaction rate of the fluorination of UO/sub 2/ by HF was measured under the condition of a gradually increasing temperature. UF/sub 4/ made in this way did not show caking although final reaction temperatures ranged as high as 700 deg C. The rate of reaction was found to be greater than the rate measured under isothermal conditions at the highest temperature attained during the continuous increase as long as this final temperature was above 550 deg C. (auth)

Report presenting data on freezing point for UNH - NH₄NO₃ - HNO₃ - H₂O Systems. A range of concentrations of systems was used and data is presented.

An X-ray - diffraction analysis of residual surface stresses after plastic strain was introduced in a parallel-sided 3S-O aluminum disk with a central hole by two types of centrifugal overspeed is reported. Both tangential and radial stresses were generally tensile with large local variations near the hole where surface stresses may have been partly superficial. These stresses were both tensile and compressive dependent on the distance from the disk center when mass compression was effected near the hole.

Abstract: The value of routine statistical tests of counter performance in the field has been investigated. The necessity for more elaborate statistical tests than those now used at the Hanford Works has not been indicated by this work.

This report is a short communication concerning the performance of pilot plant sand filters at Building 292-B at Hanford Atomic Products Operation. (VC)

From Summary: "The performance of an annular combustion chamber from a 24C turbojet engine was investigated over a range of simulated altitudes from 20,000 to 55,000 feet and corrected engine rotor speeds from 6000 to 13,000 rpm at a simulated ram-pressure ratio of 1.04. The purpose of the investigation was to determine the effects on the altitude operational limits, combustor-outlet gas temperature distribution, combustion efficiencies, and combustor inlet-to-outlet total-pressure drops of two changes in the 24C-4B basket air-passage arrangements that were designed to improve combustor-outlet temperature distribution. These changes were: (a) replacement of the downstream secondary air holes with large rectangular slots further upstream (rectangular-slot basket), and (b) enlargement of anticoking holes in the rectangular-slot basket (modified rectangular-slot basket)."

Report presenting the operational characteristics of a 20-inch ramjet with four different gutter-grid flame holders and a three-gutter flame holder with an adjustable gutter angle. The flame holders were compared on the basis of operating ranges of fuel-air ratio, combustion-chamber-inlet velocity, and the combustion efficiencies obtainable.

Memorandum presenting some pressure-distribution and boundary-layer measurements made in flight in the presence of shock on two modifications of the local contour of the wings of a high-speed airplane. Results regarding the pressure distribution, boundary-layer surveys, and effects on test airplane are provided.

Report presenting sound measurements for static conditions in a range of tip Mach numbers for three different dual-rotating-propeller configurations and one combination of two single-rotating propellers operating side by side in the same plane of rotation. The results obtained are compared with a theoretical analysis of the problem and excellent agreement is found.

"An army liaison-type airplane, representative of personal airplanes in the 150 to 200 horsepower class, has been modified to reduce propeller and engine noise according to known principles of airplane-noise reduction. Noise-level measurements demonstrate that, with reference to an observer on the ground, a noisy airplane of this class can be made quiet - perhaps more quiet than necessary. In order to avoid extreme and unnecessary modifications, acceptable noise levels must be determined" (p. 1).

Note presenting some results that have been obtained so far on ceramic coatings for molybdenum. The results indicated that the oxidation of the molybdenum was greatly retarded by the best of the ceramic coatings tried. Protection is possible in oxidizing atmospheres at gas temperatures up to 3500 degrees Fahrenheit.

Report presenting results of an experimental investigation to determine the temperature distribution in an aircraft-engine gas-turbine disk. Calculated stresses based on the measured temperature distributions are presented. Results regarding stresses in the inner region of the disk and stresses in the rim of the disk are provided.

None