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.

Report issued by the Bureau of Mines over studies conducted on the zinc-lead deposits in Cherokee County, Kansas. As stated in the introduction, "the purpose of this report is to present the factual data derived from both the preliminary examination and the subsequent field work." (p. 3). This report includes tables, and maps.

Report issued by the Bureau of Mines regarding studies conducted on iron deposits located in Meagher County, Montana. As noted in the introduction, "details of geology, sampling, and beneficiation tests are presented in this report" (p. 1). This report includes tables, maps, and illustrations.

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 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.

Report presenting an investigation of the exhaust of corrosive attack in an aluminum alloy wing employing an exhaust-gas-air mixture as a heating medium for ice prevention. There were no cases of structurally serious corrosion on either painted or plain specimens removed from the wing for detailed microscopic and metallurgic examination.

From Summary: "By the use of a form of the Prandtl-Glauert method that is valid for three-dimensional flow problems, the value of the maximum incremental velocity for compressible flow about thin ellipsoids at zero angle of attack is calculated as a function of the Mach number for various aspect ratios and thickness ratios. The critical Mach numbers (within the accuracy of the Prandtl-Glauert method) of the various ellipsoids are also determined. The results indicate an increase in critical Mach number with decrease in aspect ratio which is large enough to explain experimental results on low-aspect-ratio wings at zero lift."

Rotating-cylinder measurements of the icing conditions encountered in flight during the winter of 1947-48 are presented. Liquid water content, drop size, and temperature data are shown to be consistent with previously measured conditions and with proposed maximum icing conditions in supercooled layer-type clouds. Cumulative frequency graphs of meteorological parameters indicate the frequency with which various icing conditions have been encountered in the Great Lakes area and surrounding states.

Report presenting tests in the gust tunnel of the 30 degree sweptback wing model to provide information on some of the problems encountered in the prediction of gust loads for airplanes incorporating swept wings. The results indicate that within the scope of the data and the values of gradient distance investigated, the maximum acceleration increment depends on the slope of the lift curve of an equivalent straight wing multiplied by the cosine of the angle of sweep and on the effect of gradual penetration of the sweptback wing into the gust.

Note presenting some of the basic general equations governing the three-dimensional compressible flow of gas through a compressor or a turbine in terms of velocity components, total enthalpy, and entropy. The equations are applied to investigate the maximum compatible number of the radial variations of the gas properties between successive blade rows that a designer is free to specify.

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.

Note presenting an investigation of a two-blade and a three-blade propeller on a slender-nose fighter airplane in climb and at high speed.

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.

This document details activities at the Hanford Engineer Works during the month of December 1948.

None

Redox operations and waste metal recovery are reported. Construction in the 100-H, 100-DR, P-10 area pile areas and in the 234-5, 241-BY waste storage, and redox areas, process areas and Richland village are described. Visitor information is given. And construction progress at Schenectady is reported.

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.

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.

This semiannual report includes references in future items in the Brookhaven National Labratory program as well as an account of progress in the post six months.

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.

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 …

"A method developed in a previous report for finding the induced velocity field behind a supersonic wing with known load distribution is used to find the downwash behind a triangular wing with subsonic leading edges. Results are given for the chord plane in the extended vortex wake of the wing and for the vertical plane of symmetry up to about 20 percent of the wing span above the plane of the wing" (p. 1).

Report presenting an investigation to determine the underlying causes of the undesirable longitudinal characteristics of a 45 degree swept-forward wing in the moderate and high lift-coefficient range. Several methods were used to create a detailed correlation between separation phenomena and longitudinal characteristics of the wing. Both turbulent and leading-edge separation need to be postponed in order to improve the longitudinal characteristics of this wing.

Note presenting calculations, based on linearized supersonic flow theory and on the additional assumption that the Mach cones yaw with the wing, to determine the effect of thickness on the lateral force and yawing moment of a sideslipping delta wing at supersonic speeds. Generalized equations are derived for delta wings with rhombic profile and constant thickness ratio.