Report issued by the Bureau of Mines on the iron mines of Sussex County, New Jersey. Descriptions of the physicality, location, and drilling methods used on the deposits are presented. This report includes tables, maps, and illustrations.

The following report follows a series of experiments on the freezing points of 25 UN-H2O-HNO3 solutions.

The following document is an interim report on studies made to determine the optimum time-temperature treatment to produce a recrystallized grain structure in gamma extruded uranium."

Paper presenting a compilation of formulas, tables, and curves that have been found to be useful in the analysis of supersonic wind-tunnel data.

This report summarizes the contamination observed at the Hanford Works and vicinity for the period July, August, and September, 1947. Daily or weekly trends for all sampling locations as included in previous reports are omitted except in those cases where a true trend can be established. Statistical analysis to determine significant values and differences is used whenever possible. The report is divided into the following topic sections: meteorological -- wind conditions; extent of beta contamination in air and radiation level in air; extent of contamination in the Columbia River; extent of beta contamination in rain; extent of alpha and beta contamination in sanitary water; extent of beta contamination on vegetation; and the extent of contamination in Hanford Wastes. An appraisal and review of all the results is considered in detail for each section.

Performance curves and test results on a half scale model of the radio frequency system designed to accelerate protons in the Berkeley 184-inch cyclotron are presented. This report is a sequel to K. R. Mackenzie's report on the three quarter wave radio frequency system for frequency modulated cyclotrons.

The two-electrode vacuum tube, or diode, consists of an electron-emitting cathode surrounded by a positive anode (plate). A plot of plate current (i{sub b}) vs plate voltage (e{sub b}) is shown. At low anode voltages, the anode current is limited by the repelling effect that the negative electrons already in the space have on the electrons just being emitted (space-charge effect). When a full space charge is present, the plate current depends upon the plate voltage according to Childs law: i{sub b} {approx} e{sub b}{sup 3/2}. Increasing the plate voltage eventually results in an electron flow equal to total cathode emission, after which further increases in anode voltage will produce practically no additional current (voltage saturation). However, for high field stresses, additional electrons are pulled out of the cathode (field emission), increasing the current even further.

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This report for December, 1947 describes progress in ore dressing and pyrometallurgical studies, chemical work on phosphates, and analytical work.

This report provides a broad yet in depth overview of the use of radioactive materials as tracers in medicine and biology for the period of 1935--1947. Particular attention is paid to is of radio-sodium, radio-iodine, radio-iron, radio-phosphorus, radio-strontium, and fission products. The main thrust of this paper is human rather than animal work and focuses in work that has been published.

Report presenting a series of tests made with a CFR engine to determine the effect of inlet-valve capacity, inlet and exhaust pressure, and valve timing on the volumetric efficiency at various speeds. Three combinations of inlet and exhaust pressures and seven valve-timing arrangements were used.

Note presenting a determination of the compressive buckling stress of outstanding flanges reinforced by bulbs using the torsion-bending theory for flanges with 54 shapes and a range of lengths. The results were analyzed to determine the shape of flange that gave the greatest support to the structure to which it was attached.

Report presenting additional work in an investigation to determine the effects of preheating and postheating on the quality and strength of spot welds in aluminum alloys. The results showed that in alternating-current spot welding of aluminum alloys, the weld time is very important with regard to the quality of welds produced.

From Summary: "The Weissinger method for determining additional span loading has been used to find the lift-curve slope, spanwise center of pressure, aerodynamic center location, and span loading coefficients of untwisted and uncambered wings having a wide range of plan forms characterized by various combinations of sweep, aspect ratio, and taper ratio. The results are presented as variations of the aerodynamic characteristics with sweep angle for various values of aspect ratio and taper ratio. Methods are also included for determining induced drag and the approximate effects of compressibility."

Report presenting a method for determining the temperature and flow of heated gas necessary for ice prevention of hollow propeller blades in flight and icing conditions. A variety of conditions are taken into consideration and suggested simplifications and short methods are provided in order to not overcomplicate the design modifications.

Note presenting a verification of previously derived equations for calculating the rate of heat transfer from airfoils in icing conditions, which have come about as a result of an investigation of the meteorological conditions conducive to the formation of ice on aircraft and a study of the process of airfoil thermal ice prevention. The results indicated that knowledge of these components has increased to a point where the design of heated wings on a fundamental, wet-air basis can now be undertaken with reasonable certainty.

Investigations were made to develop a simplified method for designing exhaust-pipe shrouds to provide desired or maximum cooling of exhaust installations. Analysis of heat exchange and pressure drop of an adequate exhaust-pipe shroud system requires equations for predicting design temperatures and pressure drop on cooling air side of system. Present experiments derive such equations for usual straight annular exhaust-pipe shroud systems for both parallel flow and counter flow. Equations and methods presented are believed to be applicable under certain conditions to the design of shrouds for tail pipes of jet engines.

Note presenting an investigation to determine the interference effects of three fuselages on the readings of a pitot-static tube extending various distances forward from the noses of the fuselages. The fuselages investigated were bodies of revolution with maximum diameters equal to 12 percent of the fuselage length and with circular-nose, elliptical-nose, and pointed-nose shapes. Results regarding interference at zero angle of attack, effect of free-stream impact pressure, and effect of tube diameter are provided.

Report presenting a detailed method for determining the temperature and flow of heated gas necessary for ice prevention of hollow propeller blades in flight and icing conditions. Expressions for the total external and internal heat transfer are combined to determine the surface temperatures of each segment.

From Summary: "Results of local-instability tests of H-, Z-, and C-section plate assemblies of four extruded aluminum alloys and two magnesium alloys, obtained in an extensive investigation to determine plate compressive strengths of aircraft structural materials, are summarized. On the basis of the general relationships found between the plate compressive strengths and the compressive stress-strain curves, methods applicable to flat plates and based upon the use of the compressive stress-strain curve are suggested for determining the critical compressive stress and the average stress at maximum load."

An introduction to the problem of determining the fundamental limitations on the performance possibilities of rocket-powered aircraft is presented. Previous material on the subject is reviewed and given in condensed form along with supplementary analyses. Some of the problems discussed are: 1) limiting velocity of a rocket projectile; 2) limiting velocity of a rocket jet; 3) jet efficiency; 4) nozzle characteristics; 5) maximum attainable altitudes; 6) ranges. Formulas are presented relating the performance of a rocket-powered aircraft to basic weight and nozzle dimensional parameters. The use of these formulas is illustrated by their application to the special case of a nonlifting rocket projectile.