UNT Libraries Government Documents Department - Browse

ABOUT BROWSE FEED

The Coso Quicksilver District, Inyo County, California

Description: From abstract: The Coso quicksilver district, which is in the Coso Range, Inyo County, Calif., produced 231 flasks of quicksilver between 1935 and 1939. The quicksilver mineral, cinnabar, was not recognized in the district until 1929, although the hot springs near the deposits have been known since about 1875...The granitic rock on which much of the sinter rests is considerably altered. The cinnabar was deposited as films and grains in open spaces in the sinter, during one stage in a sequence of hot spring activities that still continues. The amount of sinter in the district is estimated to be about 1,800,000 tons. Although the greater part of this does not contain much cinnabar, the total quantity of such material is large enough to be of interest as a low-grade ore.
Date: 1943
Creator: Ross, Clyde P. & Yates, Robert G.

The Coupling of Flexural Propeller Vibrations with the Torsional Crankshaft Vibrations

Description: The exact mathematical treatment of the problem is possible by replacing the propeller blade by a homogeneous prismatic rod. Conclusions can them be drawn as to the behavior of an actual propeller, since tests on propeller blades have indicated a qualitative agreement with the homogeneous rod. The natural frequencies are determined and the stressing of the systems under the various vibration modes are discussed.
Date: December 1, 1943
Creator: Meyer, J.

Derivation of charts for determining the horizontal tail load variation with any elevator motion

Description: The equations relating the wing and tail loads are derived for a unit elevator displacement. These equations are then converted into a nondimensional form and charts are given by which the wing- and tail-load-increment variation may be determined under dynamic conditions for any type of elevator motion and for various degrees of airplane stability. In order to illustrate the use of the charts, several examples are included in which the wing and tail loads are evaluated for a number of types of elevator motion. Methods are given for determining the necessary derivatives from results of wind-tunnel tests when such tests are available.
Date: January 1, 1943
Creator: Pearson, Henry A

Description of stress-strain curves by three parameters

Description: A simple formula is suggested for describing the stress-strain curve in terms of three parameters; namely, Young's modulus and two secant yield strengths. Dimensionless charts are derived from this formula for determining the stress-strain curve, the tangent modulus, and the reduced modulus of a material for which these three parameters are given. Comparison with the tensile and compressive data on aluminum-alloy, stainless-steel, and carbon-steel sheet in NACA Technical Note No. 840 indicates that the formula is adequate for most of these materials. The formula does not describe the behavior of alclad sheet, which shows a marked change in slope at low stress. It seems probable that more than three parameters will be necessary to represent such stress-strain curves adequately.
Date: July 1, 1943
Creator: Ramberg, Walter & Osgood, William R

Determination of Flight Paths of an SBD-1 Airplane in Simulated Diving Attacks, Special Report

Description: An investigation has been made to determine the motions of and the flight paths describe by a Navy dive-bombing airplane in simulated diving attacks. The data necessary to evaluate these items, with the exception of the atmospheric wind data, were obtained from automatic recording instruments installed entirely within the airplane. The atmospheric wind data were obtained from the ground by the balloon-theodolite method. The results of typical dives at various dive angles are presented in the form of time histories of the motion of the airplane as well as flight paths calculated with respect to still air and with respect to the ground.
Date: March 1, 1943
Creator: Johnson, Harold I.

Determination of general relations for the behavior of turbulent boundary layers

Description: An analysis has been made of a considerable amount of data for turbulent boundary layers along wings and bodies of various shapes in order to determine the fundamental variables that control the development of turbulent boundary layers. It was found that the type of velocity distribution in the boundary layer could be expressed in terms of a single parameter. This parameter was chosen as the ratio of the displacement thickness to the momentum thickness of the boundary layer. The variables that control the development of the turbulent boundary layer apparently are: (1) the ratio of the nondimensional pressure gradient, expressed in terms of the local dynamic pressure outside the boundary layer and boundary-layer thickness, to the local skin-friction coefficient and (2) the shape of the boundary layer. An empirical equation has been developed in terms of these variables that, when used with the momentum equation and the skin-friction relation, makes it possible to trace the development of the turbulent boundary layer to the separation point.
Date: January 1, 1943
Creator: Von Doenhoff, Albert E & Tetervin, Neal

Determination of the Mass Moments and Radii of Inertia of the Sections of a Tapered Wing and the Center-of-Gravity Line along the Wing Span

Description: For computing the critical flutter velocity of a wing among the data required are the position of the line of centers of gravity of the wing sections along the span and the mass moments and radii of inertia of any section of the wing about the axis passing through the center of gravity of the section. A sufficiently detailed computation of these magnitudes even if the weights of all the wing elements are known, requires a great deal of time expenditure. Thus a rapid competent worker would require from 70 to 100 hours for the preceding computations for one wing only, while hundreds of hours would be required if all the weights were included. With the aid of the formulas derived in the present paper, the preceding work can be performed with a degree of accuracy sufficient for practical purposes in from one to two hours, the only required data being the geometric dimensions of the outer wing (tapered part), the position of its longerons, the total weight of the outer wing, and the approximate weight of the longerons, The entire material presented in this paper is applicable mainly to wings of longeron construction of the CAHI type and investigations are therefore being conducted by CAHI for the derivation of formulas for the determination of the preceding data for wings of other types.
Date: December 1, 1943
Creator: Savelyev, V. V.

Diesel Engines Underground: [Part] 4. Effect on Composition of Exhaust Gas of Variables Influencing Fuel Injection

Description: Report issued by the Bureau of Mines over diesel engine operations. As stated in the introduction, "it is the purpose of this report to present such data and to reemphasize the importance of adequate maintenance for diesel engines used underground" (p. 2). This report includes tables, and illustrations.
Date: April 1943
Creator: Holtz, John C.; Berger, L. B.; Elliott, M. A. & Schrenk, H. H.