Report describes the lubrication characteristics of an aircraft-type piston as visually studied in a V-type engine with a glass cylinder. Information about the movement of the piston, the piston rings, and the oil-control rings and their effect on lubrication is included.

Report presenting an analysis of the effects of heat and compressibility in the flow through the internal systems of aircraft. Equations and charts are developed whereby the flow characteristics at key stations in a typical internal system may be readily obtained.

Report presenting an investigation in the 19-foot pressure tunnel to determine the nacelle drag, the cowling-air flow, and the propeller characteristics of a model of a high-performance military airplane. The model is fitted with NACA D(sub S)-type engine cowlings and with propellers embodying NACA 16-series airfoil sections. Results regarding the propeller characteristics, drag and cowling-air flow with the propeller removed, the effect of propeller on flow through cowling, and the influence of cooling requirements on airplane performance are provided.

"The effect of two-dimensional bumps and surface waviness on the pressure distribution over airfoils is considered. It is shown that the results of the analysis may be useful in evaluating the effects of accidental or intended surface distortions on the drag and critical Mach number of airfoils" (p. 1).

From Introduction: "The purpose of this analysis was to investigate the use of function of intake-manifold temperature and pressure, exhaust back pressure, and engine speed in place of a ventri as a means of measuring engine air consumption and to determine if this function is suitable for automatic mixture control."

Included in this semi-monthly report written in 1943 are progress with neutron beams, neutron absorption in enriched materials, equipment operation and maintenance reports of the cyclotron neutron source facility, and instrumentation maintenance activities of individuals in the cyclotron group. (GHT)

Report issued by the U.S. Bureau of Mines on studies conducted at the Magnolia oil fields in Columbia County, Arkansas. History, geology, and methods are presented. This report includes tables, graphs, maps, and illustrations.

Report issued by the Bureau of Mines regarding studies on the modern petroleum engineering techniques used in Franklin County, Texas. Drilling methods, and analysis of the core samples are presented. This report includes tables, and graphs.

Report issued by the Bureau of Mines over studies conducted on the pilot plant in Laramie County, Wyoming. As stated in the introduction, "the purpose of this report is to record information derived from recent experimental work that had as its objective the development and demonstration of one method of producing sponge iron" (p. 2). This report includes tables, illustrations, and photographs.

Report issued by the Bureau of Mines over studies conducted on the Melrose zinc-lead deposits. Methods used in the investigation are listed. The characteristics of the zinc-lead deposits are presented also. This report includes tables, maps, and illustrations.

Report issued by the Bureau of Mines over studies conducted on the Blewett zinc-lead mine of Illinois. Samples obtained through churn-drill and diamond drill holes are analyzed. This report includes tables, maps, and illustrations.

Report issued by the Bureau of Mines over studies conducted on the production processes of iron-free alum. This is the second part of the report, and focuses on the development and operation of a continuous pilot plant. This report includes tables, graphs, photographs, and illustrations.

Report issued by the Bureau of Mines over mining districts in Colorado. As noted in the introduction, "in this report the physical features, climate, and ore deposits of the districts are described, and a brief history of mining and production of lead, zinc, and silver is given" (p. 4). This report includes tables, illustrations, and maps.

Report issued by the Bureau of Mines over titanium minerals in Florida. Evaluation of titanium samples obtained is presented. This report includes tables, and maps.

Among the spallation products obtained from the 350-Mev proton bombardment of Th{sup 232} they have identified two gaseous alpha-emitters which apparently do not decay into any presently known alpha-decay chains. The half-lives observed for the decay of the alpha-activities are 23 minutes and 2.1 hours. These half-lives may be principally determined by an unknown amount of orbital electron capture. At least one alpha-emitting daughter (about 4 hours half-life) has been observed to grow from a gaseous parent, but it has not been determined whether it arises from alpha-decay or electron-capture. Since these gaseous atoms emit alpha-particles it is assumed that they are isotopes of element 86 (emanation or radon) rather than a lighter rare gas. if they were heavy isotopes such as Em{sup 221} or Em{sup 223}, both unknown, they would decay into known alpha-decay series, the neptunium and actinium series, respectively, and so would grow known short lived alpha-emitters which would have been detected. It thus appears reasonable that they must be lighter than the known emanation isotopes.

Correlations of alpha-decay energies in terms of mass number and atomic number have been made for all of the alpha-emitting species now numbering over 100. For each element isotopes show increase in alpha-energy with decrease in mass number except in the region of 126 neutrons where there is an explainable reversal. This reversal has the effect of creating a region of relatively low alpha-energy and long half-life at low mass numbers for such elements as astatine, emanation, francium, and possibly higher elements as had been noted already for bismuth and polonium. Methods and examples of using alpha-decay data to define the energy surface in the heavy element region are discussed. The regularities in alpha-decay are used for predictions of nuclear properties including prediction of the beta-stable nuclides among the heavy elements. The half-life vs. energy correlations show that the even-even nuclides conform well with existing alpha-decay theory, but all nuclear types with odd nucleons show prohibited decay. The reason for this prohibition is not found in spin changes in the alpha-emission but in the assembly of the components of the alpha particle, and this theory is discussed further in terms of observations made on nuclides having two or more alpha-groups. …

Some time ago we started work in an attempt to observe alpha-particle decay in isotopes of atomic number less than 83. In the first experiments, thin targets of gold leaf were bombarded with 190-Mev deuterons in the 184-inch cyclotron. Two alpha-decay periods were observed in these targets; one of 0.7 minutes half-life and another of 4.3 minutes half-life. The alpha-particle energies were 5.7 and 5.2 Mev, respectively. Chemical separations proved that the 4.3-minute period is due to a gold isotope and suggested that the 0.7-minute period is due to a mercury isotope. The mass numbers of these new isotopes have not been determined. However, the results of excitation-functions in the production of the gold isotope by bombarding gold and platinum with protons suggest that its mass number lies in the range 185-188. The work on this isotope indicates that the alpha to electron capture branching ratio is of the order of magnitude of 10{sup -4}, and that positron activity accompanies the 4.3-minute alpha-period.

At the spring, 1949, meeting of the National Academy of Sciences(l) a preliminary account was given of some observations of mesons produced by the 335 Mev x-ray beam from the Berkeley synchrotron. The present paper is a progress report of this work; no claim is made for completeness, but sufficient new data are available to make publication at this time worth while, especially since some of the numerical results given in the earlier report require revision. The x-ray beam, produced by the impact of 335 Mev electrons on a 20 mil thick platinum target, has a width at half maximum of 0.0135 radian (about 1 inch at 6 feet from the target). In all but the earliest experiments the beam was further defined by a 1 inch hole in a lead block, then passed through a piece of carbon which served as the meson source. The x-ray intensity at one meter from the target was about 3500 r per hour (measured behind 1/8 inch of lead) under the best running conditions; the average was about half this. The actual exposures at the carbon meson source (6 feet from the target) ranged from 500 to 2000 r in the later runs. …

This is a progress report on the following: (1) 184-inch Cyclotron Program; (2) 60-inch Cyclotron Operation; (3) Synchrotron Program; (4) Linear Accelerator Operation; (5) Experimental Physics; (6) Theoretical Physics; (7) Isotope Separation Program; (8) Chemistry; (9) Medical Physics; and (10) Health Chemistry and Physics.

Abstract: "A method is described for the identification and quantitative determination of trace amounts of rare earths in graphite by measurement of the energies and decays of the activities induced by neutron irradiation. The specific rare earth elements identified are europium and samarium. During the development of this method, the half-lives of Eu-152 and Sm-153 were determined. These are reported as 9.32 +/- 0.04 hours and 46.34 +/- 0.23 respectively."

This report is a document summarizing all information available on life aspects of various measures proposed to reduce or eliminate corrosion of Van Stone flanger.

Report discussing a method for the stepwise calculation of the number of transfer units utilized in a given solvent extraction operation. "Use of the method results in a very appreciable saving in time of calculation with an error of 1.5% for the runs tested. The error tends to become smaller with increasing total numbers of transfer units involved."

From introduction: "The present investigation of the properties of boron stainless steel is an outgrowth of a project started in 1947. The problem is to replace the present steel used for drop rods in the Hanford piles with a material much less subject to corrosive attack from the humid atmosphere existing at the location of the rods."

Note presenting an analysis of the use of the Prandtl-Glauert method for subsonic potential flow of a compressible fluid. This paper specifically focuses on the difference between the two- and three-dimensional flow when using this method.