Abstract: Various procedures for extracting uranium from fiberglass air filters have been tested and compared. Satisfactory results which involve the least amount of handling are obtained by simply washing the material with hot 1:1 hydrochloric acid.

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The decay scheme of a 4.2 second neutron emitter has been investigated in detail. Chemical and physical evidence shows that it is N{sup 17}, which emits beta rays to a broad excited state of O{sup 17}, which then breaks up into a neutron plus O{sup 16}. The energy spectrum of the neutrons is determined by measuring the energies of the O{sup 16} recoils in a proportional counter. The neutrons have a most probable energy of 0.9 Mev, a 'half width' of less than .5 Mev, and an upper limit of about 2 Mev. {beta}-recoil coincidences are observed, as predicted by the Bohr-Wheeler theory, and the {beta}-ray energy is measured by absorption. The beta rays in coincidence with neutrons have an upper limit of 3.7 {+-} 0.2 Mev. Beta-rays directly to the ground stat of O{sup 17} are not observed because of high background effects, but should have an energy of 8.7 Mev. Some evidence is presented to show that energy is conserved in the {beta}-n transition through the broad excited state in O{sup 17}.

Monthly progress report filled out by the Austin chapter of the the American Women's Voluntary Services discussing their news and activities.

Introduction. the conventional procedures of analysis for uranium and manganese can be employed in the analysis of alloys of these metals. The alloys are reacted with perchloric acid and hydrogen peroxide, fumed to remove any chloride ions, diluted to volume and aliquots analyzed by redoximetry.

Introduction. It has been known for a long time that thorium is precipitated by oxalic acid in acid solutions, but a survey of the literature showed no study of the limits of the acidity and oxalic acid excess which yield quantitative results. V. I. Spitzin reports on the solubility of thorium oxalate in varying concentrations of several acids, but the effect of an excess oxalic acid is not included. Since solutions are sometimes presented for analysis that contain more than the recommended two per cent mineral acid, it would be advantageous to be able to quantitatively remove the thorium without otherwise altering the solutions. This was especially of interest in solutions containing bismuth, since it was hoped that some amounts of thorium could be precipitated in nitric acid solutions containing large quantities of bismuth. In removing the bismuth, first by a bismuth oxychloride precipitation, thee is every opportunity for carrying of the thorium.

Report presenting the results of testing in the transonic range of four flutter airfoils attached to a freely falling body. Failures of the airfoils were metered and recorded in order to determine the Mach numbers and altitudes of failure.

"The tests reported herein were made for the purpose of determining the high-speed load distribution on the wing of a 3/16 scale model of the Douglas XSB2D-1 airplane. Comparisons are made between the root bending moment and section torsional moment coefficients as obtained experimentally and derived analytically. The results show good correlation for the bending moment coefficients but considerable disagreement for the torsional moment coefficients, the measured moments being greater than the analytical moments. The effects of Mach number on both the bending moment and torsional moment coefficients were small" (p. 1).

From introduction: "The concluding remarks of the report on the electron diffraction study of UF6 suggest two alternate explanations for the apparent discrepancy between the structure proposed for this compound as deduced from X-ray diffraction work on single crystals and from the electron diffraction investigation of the vapor. The second explanation is based on the premise that the difference may be due to essentially unlike methods of treating the diffraction data. In this report we shall analyze X-ray powder photographs following a scheme parallel to that used in the analysis of the electron diffraction data, to check whether this particular explanation is tenable."

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The following report describes the methods of chemical conversion of uranium fluoride to uranium trioxide.

This study was undertaken to determine the maximum temperatures that may be expected in slugs under various operating power levels. Information of this nature is required to properly evaluate the effects on the slug of pile operation at power levels higher than those currently in use.

From Summary: "A theoretical investigation of the velocity profiles for laminar mixing of a high-velocity stream with a region of fluid at rest has been made assuming that the Prandtl number is unity. A method which involves only quadratures is presented for calculating the velocity profile in the mixing layer for an arbitrary value of the free-stream Mach number. Detailed velocity profiles have been calculated for free-stream Mach numbers of 0, 1, 2, 3, and 5."

Business and Legislation report from the Research Institute of America containing a confidential analysis and recommendations for its members. The report contains an outline for dealing with inflation and instructions for operation under a new tax law.

From experience gained by NACA test pilots in flying at high subsonic Mach numbers and from interpretation of the data obtained, some general precautionary rules for test flying near sonic Mach numbers have been formulated. The reasons for these rules are discussed and observations are made with respect to the hazards arising from undesirable stability and control characteristics which have been noted in test flights of various airplanes. This paper, although written primarily for the attention of test pilots, contains general information of interest to those who are concerned with various phases of flight testing near sonic Mach numbers.

Report presenting a wind-tunnel investigation of a semispan pointed wing of aspect ratio 1.7 with 60 degree leading-edge sweepback and 30 degree trailing-edge sweepforward with a control surface. The purpose of the investigation was to determine the effectiveness of flap-type controls at transonic and supersonic speeds. Results regarding the wing characteristics and control-surface characteristics are provided.

"In order to determine the aerodynamic effects of an auxiliary belly fuel tank on the Grumman F8F-1 airplane, a wind-tunnel investigation was made on a 1/5 - scale model of the Grumman XF8F-1 airplane. Pitch and yaw tests were made with the model in the cruising and landing configurations for windmilling and take-off power conditions. Tuft studies and static-pressure measurements were also made to determine the flow characteristics in the region of the fuel tank" (p. 1).

Report discussing testing on two types of single cylinders to determine the effect of the relation of exhaust pressure to inlet-air pressure on knock-limited performance. Variables explored included exhaust pressure, fuel-air ratio, and engine speed. Three types of fuels were also used to explore the effect of exhaust pressure on fuel ratings.

The study was made in an effort to determine experimentally the relationship between Logac 1,2 counts and the thickness of the slide on which a sample is mounted.

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Report presenting an investigation to obtain the pressure distribution over a sharp-nose body of revolution with a circular-arc profile and fineness ratio 6 at transonic speeds using the NACA wing-flow method. Results regarding the variation of pressure coefficient with Mach number, pressure distributions along the body axis, pressure drag, and effects of interference and horizontal gradient are provided.

The following report describes and foretells the situation in medium in which neutrons are being (a)produced as fast neutrons, (b) slowed down to thermal speeds by impacts with nuclei, and (c) absorbed by nuclei in such a manner that sometimes fresh fast neutrons appear at the place where a thermal neutron has just appeared.

Operating characteristics of the 11-stage 4000-pound-thrust axial-flow turbojet engine were determined. A standard compressor and a compressor with the blade angles of the rotor and stator blades increased 5 degrees to obtain greater air flow, were investigated.

"Available information on gust structure, airplane reactions, and pertinent operating statistics has been examined. This report attempts to coordinate this information with reference to the prediction of gust loads on airplanes. The material covered represents research up to October 1947" (p. 807).