This report presents the results of an investigation to determine the variations in intensity and spectral distribution of the radiant energy emitted by the flames during normal and knocking explosions in an engine. Radiation extending into the infrared was transmitted by a window of fluorite, placed either near the spark plug or over the detonation zone at opposite ends of the combustion chamber. Concave, surface-silvered mirrors focused the beam, first at the slit of a stroboscope which opened for about 2 degrees of crank angle at any desired point in the engine cycle, and then upon the target of a sensitive thermocouple for measuring radiation intensity.

"Another extraction method is described herein for the quantitative recovery of tuballoy from solutions containing high concentrations of fluoride ion. The method consists of the addition of aluminum nitrate to the solution in order to complex the fluoride ion, followed by saturation with calcium nitrate and extraction of the tuballoy with dibutyl carbitol.

From Summary: "Tests of two-blade propellers having the NACA 4-(3)(06.3)-06 and NACA 4-(3)(06.4)-09 blade designs (blade activity factors of 179 and 263, respectively) have been made in the Langley 8-foot high-speed tunnel through a range of blade angle from 20 degrees to 70 degrees for free-stream Mach numbers from 0.165 to 0.725 to determine the effects of high solidity and compressibility on propeller characteristics. The tests are part of a general investigation of propellers at high forward speeds. Results previously reported for similar tests of two-blade propellers having the NACA 4-308-03 and NACA 4-308-045 blade designs (blade activity factors of 87 and 133, respectively) are included for comparison. The results showed that the 0.06- and 0.09-solidity blades, although producing efficiencies of the order of 90 percent, were less efficient than blades of conventional solidity."

This technical progress letter contains reports from six Technical Department divisions at the Hanford Engineer Works for February 16 through February 22, 1947. The six reporting divisions are: 100 Areas, 300 Area, 200 Areas, Chemical Development, Laboratories, and Statistical Studies. (JL)

"The XF-12 airplane is a high-performance photo-reconnaissance aircraft designed for the Army Air Forces by the Republic Aviation Corporation. An investigation of a 1/8.33 - scale powered model was made in the Langley l9-foot pressure tunnel to obtain information relative to the aerodynamic design of the airplane. The model was tested with and without the original vertical tail. and with two revised tails. For the revised tail no. 1, the span of the original vertical .tail was increased about 15 percent and the portion of the vertical tail between the stabilizer and fuselage behind the rudder hinge line was allowed to deflect simultaneously with the main rudder" (p. 1).

Report presenting high-speed wind tunnel testing of horn- and overhang-balance elevators on a full-scale, semispan, horizontal tail. The effects of unshielding the horn and unsealing the overhang were investigated. Results regarding aerodynamic characteristics, distortions of the tail, and critical Mach numbers are provided.

Fission product distribution, fission product activities, and decontamination factors are terms of general usage in the Chemical Development Section. Specific values for some of these terms have been based upon data procured several years ago. In many cases more accurate basic numbers are now available. This report sets forth in tabular form detailed information on fission product activities as a function of decay time for certain conditions. It attempts to quality the use of the theoretical curie as a unit of activity to a unit having a more direct practical significance, the ``countable curie.``

Definite identification has been made of an isotope of the element with atomic number 98 through the irradiation of Cm{sup 242} with 35 Mev helium ions in the Berkeley Orocker Laboratory 60-inch cyclotron. The isotope which has been identified has an observed half-life of about 45 minutes and probably has the mass number 244. The observed mode of decay of the 98{sup 244} is through the emission of alpha-particles, with energy about 7.1 Mev, which agrees with predictions, and other considerations involving the systematics of radioactivity in this region indicate that it should also be unstable toward decay by electron-capture. The chemical separation and identification of the new element was accomplished through the use of ion exchange adsorption methods employing the resin Dowex-50. The element 98 isotope appears in the eka-dysprosium position on elution curves containing 4.6-hour Bk{sup 243} (formed by a d,n reaction in the same bombardment) and the bombarded Cm{sup 242} as reference points; that is, it preceded berkelium and curium off the column just as dysprosium precedes terbium and gadolinium. The experiments so far have revealed only the tripositive oxidation state of eka-dysprosium character but practically no attempts at oxidation to possible IV and V states have …

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NACA instrumentation has been installed in the X-4 airplanes to obtain stability and control data during the acceptance tests conducted by the Northrop Aircraft Corporation. This report presents data obtained on the stalling characteristics of the airplane in the clean and gear- down configurations. The center of gravity was located at approximately 18 percent of the mean aerodynamic chord during the tests. The results indicated that the airplane was not completely stalled when stall was gradually approached during nominally U accelerated flight but that it was completely stalled during a more abruptly approached stall in accelerated flight. The stall in accelerated flight was relatively mild, and this was attributed to the nature of the variation of lift with angle of attack for the 001-614 airfoil section, the plan form of the wing, and to the fact that the initial sideslip at the stall produced (as shown by wind-tunnel tests of a model of the airplane) a more symmetrical stall pattern.

Report presenting an investigation to evaluate the engine service performance of nozzle-diaphragm blades of AISI 321 and AISI 347 stainless steels. Data were obtained from three nozzle diaphragms alternately bladed with each of the two materials. Results regarding a visual inspection, a metallurgical examination, the mechanism of cracking, and the classification of failures are provided.

Technical report detailing expansion of the Aircraft Nuclear Propulsion at the Oak Ridge National Laboratory. Major facilities completed at this time were the Shielding Rector, the ANP Critical Facility, and the 86-in. Cyclotron. Outlines further need for radiation damage studies. [From Summary]

Abstract: "The counting efficiency of Pa²³³ has been determined by comparison of the counting rate of Pa²³³, under stated conditions, with the disintegration rate of U²³³ produced by Pa²³³ decay."

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A considerable volume of work was accomplished during the past three months in the tracer program, experiments being conducted with At{sup 211}, carrier-free Bi{sup 206}, carrier-free Mn{sup 52}, carrier-free Mo{sup 93,99}, Np{sup 237}, Ta{sup 182} of a fair degree of specific activity, carrier-free Sc{sup 46}, and high specific activity Tm{sup 170}.

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First 31 pages of a quarterly report discussing the progress made on research projects during the period from October 1950 to December 1950. This section of the report discusses progress on studies of the metabolic properties of various elements.

From introduction: The Monument No. 2 mine is in the Navajo Indian Reservation, Apache County, Arizona, about 20 miles southwest from the San Juan River at Mexican Hat, Utah, and 26 miles southwest from Mexican Water, Arizona. The property has been operated, since its discovery, by Vanadium Corporation of America, which holds a 10-year mining lease, granted through the Interior Department, to 43 acres of ground. History of the discovery of the deposit is vague, but reportedly it was first seen around 1942 by a Navajo who mentioned the occurrence to Harry Goulding, Indian trader, who in turn advised D. W. Viles of Vanadium Corporation of America. Minor portions of the deposit are held by Cato Sells and Harvey Black, Navajos, under mining permits issued by the Navajo Tribal Council. The Sells acreage is being operated by Climax Uranium Corporation.

The performance of MIL-F-5624A fuels, grades JP-3 and JP-4, was investigated in an axial-flow turbojet engine over a range of altitude conditions of 10,000 to 55,000 feet. Examination of the fuel flow, combustion efficiency, and net thrust specific fuel consumption showed the grade JP-4 fuel to be slightly inferior to the grade JP-3 fuel, although the altitude ignition limits were essentially equal for the two fuels over a range of flight Mach numbers and fuel-inlet temperatures.

A study of two 20 degrees half-angle, low mass-flow ratio conical supersonic inlets with cone boundary-layer bleed was made on a 16-inch ram-jet engine in the Lewis 8- by 6-foot supersonic wind tunnel. A greater stable subcritical range of operation was obtained with the bleed inlets than with the corresponding inlet without boundary-layer bleed. The drag added by the bleed system was small.

A study of a 20 degree and a 25 degree half-angle high mass-flow ratio conical supersonic inlet was made on a 16-inch ram jet in the 8- by 6-foot supersonic tunnel. A greater range of stable subcritical operation was obtained with the low mass-flow ratio inlets; a greater range was obtained with the 25 degree than with the 20 degree half-angle low mass-flow ratio inlet. The high mass-flow ratio inlet had the least drag.

Daily cash report for Imperial Sugar Company including a list of large withdrawals for the months surrounding the date showing the daily expenses and estimated balance for each entry. It also lists scheduled payments for bank loans.

The following report describes a beta and gamma scintillation detector similar to what was used in previous decay studies, yet was modified to make it suitable for the analysis of mixtures of radio-nuclides.

Varying amounts of radiation decomposition during storage in the dry form have been found in the cases of C{sup 14}-labeled valine, norvaline, norleucine, choline chloride, calcium glycolate and cholesterol. These data indicate that investigators using labeled organic compounds should make frequent checks of the purity of these compounds in order to exclude the possibility of the presence of decomposition products.