The following report describes two rapid, micro methods for the determination of UNH in Redox waste samples that had been developed fir the concentration range 0.2 to 100 g/l.

N{sup 12} is shown to have a half life of 12.5 {+-} 1 milliseconds, and a positron upper limit of 16.6 {+-} 0.2 Mev. It is produced by the reaction C{sup 12}(p,n)N{sup 12}, and has a threshold proton energy of 20.0 Mev. This indicates that N{sup 12} is within about 200 Kev of being unstable against proton emission. The mass of N{sup 12} is 12.0228 {+-} 0.00015, and the beta transition is allowed.

"The flexural vibration of a rotating propeller blade with clamped shank is analyzed with the object of presenting, in matrix form, equations for the elastic bending moments in forced vibration resulting from aerodynamic forces applied at a fixed multiple of rotational speed. Matrix equations are also derived which define the critical speeds end mode shapes for any excitation order and the relation between critical speed and blade angle. Reference is given to standard works on the numerical solution of matrix equations of the forms derived" (p. 1).

This is the progress report for the University of California, Radiation Laboratory for December 15, 1948-January 15, 1949. It discusses the following: (1) Bevatron; (2) 184-inch Cyclotron Program; (3) 60-inch Cyclotron Program; (4) Synchrotron Operation; (5) Linear Accelerator and Van de Graaff Operation; (6) Experimental Physics; (7) Theoretical Physics, (8) Isotope Separation; (9) Chemistry Departments; (10) Medical Physics; and (11) Health Physics and Chemistry.

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Contains results of calculations made to determine the neutral oscillatory stability boundaries, period and time to damp of the oscillatory mode, and motions following disturbances. The calculations were made for Mach numbers of 0.75 and 2.3 at an attitude of 35,000 feet and for the landing condition at sea level.

Report presenting generalized radiation charts for the calculation of the irradiation from water vapor, carbon dioxide, ozone, and the earth in terms of appropriate parameters. Nocturnal irradiation was found to decrease greatly as a function of altitude and meteorological conditions.

Prior to April 1948 the generally accepted method of reducing the radioactive contamination of metal tools and laboratory apparatus was a series of rinses in aqua regia or various other concentrated acids. This method proved unsatisfactory for three reasons. (A) It was not a dependable method of removing activity. (B) It had a delecterious effect on tools in that it caused serious pitting, which resulted in weakened parts, and exposed a bare metal that was subject to very rapid corrosion. (C) Tools and apparatus once cleaned by this method could not readily be cleaned a second time. With the aforementioned limitations in mind, it became obvious that a new method was required. After considerable investigation into a electrochemical processes the present method was developed. Essentially, the new method is an electropolish bath to remove the activity lodged in the pores of the metal, and a ``follow-up`` chrome plate bath to render the surface impassive to corrosion.

The supersonic method of cleaning glassware is an outgrowth of the fact that it has been heretofore impossible to manually clean ground glass and quartz joints because the activity became lodged in the small pores of the ground surfaces. It has been theorized that the nature of the forces binding polonium to the glass is similar to that of the chemical bond but are less intense. The problem then becomes one of finding a force greater than this binding energy, capable of freeing the activity from the glass. This has been accomplished by using frequencies of 100 cycles to 20 kc at a power output from 2 to 20 watts, passing through a citric acid solution (pH-2) into which the contaminated article is placed. The optimum results, using a tank with the dimensions 7 in. {times} 7 in. {times} 7 in. and 3 liters of solution, has been found at 200 cycles or harmonics of 200 cycles. Citric acid was used because of the fact that it forms a soluble complex with polonium. The frequencies used have been kept within the sonic range until enough data has been obtained and correlated to warrant the design and construction of more costly …

Abstract. Experimental work was carried out to improve material conversion efficiency and to reduce handling costs inherent in the present process for production of high purity calcium. Charges up to 54 pounds were handled successfully in the equipment available. Material losses were reduced and more complete removal of alkali and alkaline earth metals was effected by controlled pressures of inert gas and by melting under positive pressure of Argon.

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.

Report presenting an investigation of the take-off and landing behavior in waves of models of a hypothetical flying boat with hull length-beam ratios of 6 and 15. The flying boat had a design gross weight of 75,000 pounds, a wing loading of 41.1 pounds per square foot, and a power loading of 11.5 pounds per brake horsepower for take-off. Results regarding the landing behavior, spray characteristics, and taxiing and take-off behavior are provided.

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."

Note presenting landing tests made with the PB2Y-6 flying boat to determine the effect of production step vents and forebody longitudinal steps on skipping. Skipping was found to occur at higher landing trims without either step vents or longitudinal steps. The steps were found to constitute a powerful method for improving the landing stability.

Report issued by the Bureau of Mines regarding studies conducted on lead-zinc mines in Stevens County, Washington. As stated in the introduction, "this report presents the factual data obtained from the trenching and sampling operations" (p. 1). This report includes tables, maps, and illustrations.

This is a report on Analytical Services of the Pile Area Laboratories at Hanford. Pertinent facts are listed regarding the analytical services currently provided by the Analytical Section in the pile areas. The work of the Analytical Section in the pile areas may be classified into five categories as follows: Analysis of pile process water, analysis of power plant (boiler) waters, analysis of drinking water, analysis of columbia (non-process) and Yakima River water, and preparation of reagents and standard solutions.

Report presenting comparisons of the structural efficiency of panels with straight-web and curved-web Y-section stiffeners. In the high-stress region in which failure is at least in part associated with local buckling, panels with curved-web Y-section stiffeners have higher structural efficiencies than panels with straight-web Y-section stiffeners, which is evidenced by higher average stresses at failure, smaller stiffener heights, or wider average spacing of rivet lines.

"Direct-reading design charts are presented for 24S-T aluminum-alloy flat compression panels having longitudinal formed Z-section stiffeners. These charts make possible the direct determination of the stress and all the panel proportions required to carry a given intensity of loading with a given skin thickness and effective length of panel" (p. 1).

"Direct-reading design charts are presented for 24S-T aluminum-alloy flat compression panels having longitudinal straight-web Y-section stiffeners. These charts make possible the direct determination of the stress and all the panel proportions required to carry a given intensity of loading with a given skin thickness and effective length of panel" (p. 1).

Note presenting a prismatic-float forebody with an angle of dead rise of 40 degrees that was subjected to smooth-water impacts in the impact basin. The tests were made at fixed trims of 3, 6, 9, and 12 degrees for a range of flightpath angles from approximate 2 to 22 degrees. The data are presented and converted into dimensionless variables for correlation of the experimental results with hydrodynamic impact theory and for comparison of the runs among themselves.

Note presenting a wind-tunnel investigation made of the lateral-control characteristics of a thin, low-drag, semispan wing equipped with three configurations of circular plug ailerons and a full-span, 25-percent-chord, slotted flap. The investigation was performed through a Mach number range of 0.13 to 0.61. Results regarding wing aerodynamic characteristics, aileron control characteristics, comparison of lateral-control characteristics of the three configurations of circular plug aileron, comparison of lateral-control characteristics of the circular plug ailerons, a conventional plug aileron, and a retractable aileron, and a comparison of lateral-control characteristics of the circular plug ailerons with those of a sealed plain aileron are provided.

A method is developed whereby the fundamental mechanisms are investigated by which processing, heat treatment, and chemical composition control the properties of alloys at high temperatures. The method used metallographic examination -- both optical and electronic --studies of x-ray diffraction-line widths, intensities, and lattice parameters, and hardness surveys to evaluate fundamental structural conditions. Mechanical properties at high temperatures are then measured and correlated with these measured structural conditions. In accordance with this method, a study was made of the fundamental mechanism by which aging controlled the short-time creep and rupture properties of solution-treated low-carbon n-155 alloy at 1200 degrees F.

Report presenting an investigation of the effect of the rate of change of angle of attack on the maximum lift coefficient of a pursuit airplane equipped with a low-drag-type wing in stalls of varying abruptness over a range of Mach and Reynolds numbers. Maximum lift coefficients were found to increase linearly with increasing rate of change of angle of attack per chord length of travel up to the maximum rate attained in the tests.

Monthly report of the U.S. Geological Survey's trace element investigations including an outline of field work, laboratory work, and staff activities that have been completed or are in process.