Systematics of Alpha-Radioactivity (open access)

Systematics of Alpha-Radioactivity

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. …
Date: September 12, 1949
Creator: Perlman, I.; Ghiorso, A. & Seaborg, G. T.
System: The UNT Digital Library
Life of Van Stone Corrective Measures (open access)

Life of Van Stone Corrective Measures

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.
Date: September 12, 1949
Creator: Botsford, C. W. & Eschbach, E. A.
System: The UNT Digital Library
Stepwise Calculation for the Determination of the Number of Transfer Units in Countercurrent Extraction Columns (open access)

Stepwise Calculation for the Determination of the Number of Transfer Units in Countercurrent Extraction Columns

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."
Date: September 12, 1949
Creator: Burns, W. A. & Eschbach, E. A.
System: The UNT Digital Library
Hydrodynamic characteristics of a swept planing-tail hull (open access)

Hydrodynamic characteristics of a swept planing-tail hull

Report presenting the hydrodynamic characteristics of a swept planing-tail hull as determined by water tank testing. The hull shape was based on results from previous testing indicating that symmetrical airfoil sections and slender boom-like afterbodies lower the drag. Results regarding spray characteristics, take-off stability and trims, landing stability, resistance, and directional stability are presented.
Date: September 12, 1949
Creator: McKann, Robert E.; Coffee, Claude W. & Arabian, Donald D.
System: The UNT Digital Library
Preliminary Wind-Tunnel Investigation at High-Subsonic Speeds of Planing-Tail, Blended, and Airfoil-Forebody Swept Hulls (open access)

Preliminary Wind-Tunnel Investigation at High-Subsonic Speeds of Planing-Tail, Blended, and Airfoil-Forebody Swept Hulls

Report presenting an investigation in the high-speed 7- by 10-foot tunnel to determine the high-subsonic aerodynamic characteristics of three different types of flying-boat hull: a planing-tail hull, a blended hull, and an airfoil-forebody swept hull.
Date: September 12, 1949
Creator: Riebe, John M. & MacLeod, Richard G.
System: The UNT Digital Library
A comparison of the experimental subsonic pressure distributions about several bodies of revolution with pressure distributions computed by means of the linearized theory (open access)

A comparison of the experimental subsonic pressure distributions about several bodies of revolution with pressure distributions computed by means of the linearized theory

Report presenting an analysis of the effects of compressibility on the pressure coefficients of several bodies of revolution by comparing experimentally determined pressure coefficients with corresponding pressure coefficients calculated by the use of linearized equations of compressible flow. The results indicated that the theoretical methods predict the subsonic pressure-coefficient changes over the central portion of the body but do not predict the pressure-coefficient changes near the nose.
Date: September 12, 1949
Creator: Matthews, Clarence W.
System: The UNT Digital Library
Preliminary analysis of axial-flow compressors having supersonic velocity at the entrance of the stator (open access)

Preliminary analysis of axial-flow compressors having supersonic velocity at the entrance of the stator

Report presenting a supersonic compressor design with supersonic velocity at the entrance of the stator on the assumption of two-dimensional flow. The rotor and stator losses assumed in the analysis are based on the results of preliminary supersonic cascade tests. The starting conditions and stability of the flow in rotor and stator are discussed, and the desirability of the variable-geometry stators and adjustable guide vanes is indicated.
Date: September 12, 1949
Creator: Ferri, Antonio
System: The UNT Digital Library
Analytical and Experimental Investigation of 90 Degrees Supersonic Turning Passages Suitable for Supersonic Compressors or Turbines (open access)

Analytical and Experimental Investigation of 90 Degrees Supersonic Turning Passages Suitable for Supersonic Compressors or Turbines

"Four 90 degree two-dimensional turning passages designed by the method of characteristics were tested at an inlet Mach number of 1.71. The measured losses varied from 5 to 15 percent of the inlet stagnation pressure. The smallest loss was obtained for a passage in which separation on the convex surface was minimized through the introduction of a favorable pressure gradient" (p. 1).
Date: September 12, 1949
Creator: Liccini, Luke L.
System: The UNT Digital Library
Dislocation Theory of the Fatigue of Metals (open access)

Dislocation Theory of the Fatigue of Metals

"A dislocation theory of fatigue failure for annealed solid solutions is presented. On the basis of this theory, an equation giving the dependence of the number of cycles for failure on the stress, the temperature, the material parameters, and the frequency is derived for uniformly stressed specimens. The equation is in quantitative agreement with the data" (p. 183).
Date: September 12, 1947
Creator: Machlin, E. S.
System: The UNT Digital Library
Progress Report for the month of August 1945 (open access)

Progress Report for the month of August 1945

None
Date: September 12, 1945
Creator: unknown
System: The UNT Digital Library
Preliminary Analysis of Axial-Flow Compressors Having Supersonic Velocity at the Entrance of the Stator (open access)

Preliminary Analysis of Axial-Flow Compressors Having Supersonic Velocity at the Entrance of the Stator

"A supersonic compressor design having supersonic velocity at the entrance of the stator is analyzed on the assumption of two-dimensional flow. The rotor and stator losses assumed in the analysis are based on the results of preliminary supersonic cascade tests. The results of the analysis show that compression ratios per stage of 6 to 10 can be obtained with adiabatic efficiency between 70 and 80 percent. Consideration is also given in the analysis to the starting, stability, and range of efficient performance of this type of compressor" (p. 1).
Date: September 12, 1949
Creator: Ferri, Antonio
System: The UNT Digital Library