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Results of a Biological Survey of Mount Shasta California

Description: From introduction: "Biological survey of northern California from the Madeline Plains to the Pacific Ocean and from the Oregon boundary to Lassen Butte and parts of the Sierra, with Mount Shasta occupying a nearly central position."
Date: October 28, 1899
Creator: Merriam, C. Hart
Partner: UNT Libraries Government Documents Department
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Efflux of Gases Through Small Orifices

Description: Scientific paper issued by the Bureau of Standards over studies conducted on gas effusion rates. The methods used and the results of the studies are presented and discussed. This paper includes tables, and illustrations.
Date: January 28, 1920
Creator: Buckingham, Edgar & Edwards, Junius David
Partner: UNT Libraries Government Documents Department
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A New Interferential Dilatometer

Description: Scientific paper issued by the Bureau of Mines over development of a dilatometer. The instrument is used in tests of thermal expansion. The methods are presented and discussed. This paper includes an illustration.
Date: February 28, 1920
Creator: Priest, Irwin G.
Partner: UNT Libraries Government Documents Department
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A Biological Survey of Alabama

Description: Booklet describing the biology of Alabama in two sections: (1) physiography and life zones, and (2) mammals. It also includes an annotated species list of mammals, bibliography, and index starting on page 81.
Date: October 28, 1921
Creator: Howell, Arthur H.
Partner: UNT Libraries Government Documents Department
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Geology of the Wiles Area Ranger District, Texas

Description: This report describes the economic geology of the Wiles area Ranger District, Texas.
Date: June 28, 1922
Creator: Dobbin, Carroll E.
Partner: UNT Libraries Government Documents Department
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Water pressure distribution on a twin-float seaplane

Description: This is the second of a series of investigations to determine water pressure distribution on various types of seaplane floats and hulls, and was conducted on a twin-float seaplane. It consisted of measuring water pressures and accelerations on a TS-1 seaplane during numerous landing and taxiing maneuvers at various speeds and angles. The results show that water pressures as great as 10 lbs. per sq. in.may occur at the step in various maneuvers and that pressures of approximately the same magnitude occur at the stern and near the bow in hard pancake landings with the stern way down. At the other parts of the float the pressures are less and are usually zero or slightly negative for some distance abaft the step. A maximum negative pressure of 0.87 lb. Per square inch was measured immediately abaft the step. The maximum positive pressures have a duration of approximately one-twentieth to one-hundredth second at any given location and are distributed over a very limited area at any particular instant.
Date: December 28, 1928
Creator: Thompson, F. L.
Partner: UNT Libraries Government Documents Department
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Aircraft Accidents: Method of Analysis

Description: The revised report includes the chart for the analysis of aircraft accidents, combining consideration of the immediate causes, underlying causes, and results of accidents, as prepared by the special committee, with a number of the definitions clarified. A brief statement of the organization and work of the special committee and of the Committee on Aircraft Accidents; and statistical tables giving a comparison of the types of accidents and causes of accidents in the military services on the one hand and in civil aviation on the other, together with explanations of some of the important differences noted in these tables.
Date: January 28, 1930
Creator: Committee on Aircraft Accidents
Partner: UNT Libraries Government Documents Department
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Investigation of damping liquids for aircraft instruments 2

Description: "Data are presented on the kinematic viscosity, in the temperature range -50 degrees to +30 degrees C. of pure liquids and of solutions of animal oils, vegetable oils, mineral oils, glycerine, and ethylene glycol in various low freezing point solvents. It is shown that the thermal coefficient of kinematic viscosity as a function of the kinematic viscosity of the solutions of glycerine and ethylene glycol in alcohols is practically independent of the temperature and the chemical composition of the individual liquids. This is similarly true for the mineral oil group and, for a limited temperature interval, for the pure animal and vegetable oils. The efficiency of naphthol, hydroquinone, and diphenylamine to inhibit the change of viscosity of poppyseed and linseed oils was also investigated" (p. 679).
Date: March 28, 1931
Creator: Houseman, M. R. & Keulegan, G. H.
Partner: UNT Libraries Government Documents Department
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Pressure-distribution measurements on the hull and fins of scale model of the U. S. Airship "Akron"

Description: This report presents the results of measurements of pressure distribution conducted in the propeller-research wind tunnel of the National Advisory Committee for Aeronautics on a 1/40-scale model of the U. S. Airship "Akron" (ZRS-4). The pressures, which were measured simultaneously at nearly 400 orifices located at 26 stations along one side of the hull, were recorded by two photographic multiple manometers placed inside the model. The hull pressures were measured both with and without the tail surfaces and the control car for eight angles of pitch varying from 0 degree to 20 degrees and at air speeds of approximately 70 and 100 miles per hour. The pressures were also measured at approximately 160 orifices on one horizontal fin for the above speeds and pitch angles and for nine elevator angles.
Date: June 28, 1932
Creator: Freeman, Hugh B.
Partner: UNT Libraries Government Documents Department
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The N.A.C.A. High-Speed Wind Tunnel and Tests of Six Propeller Sections

Description: "This report gives a description of the high-speed wind tunnel of the National Advisory Committee for Aeronautics. The operation of the tunnel is also described and the method of presenting the data is given. An account of an investigation of the aerodynamic properties of six propeller sections is included" (p. 399).
Date: March 28, 1933
Creator: Stack, John
Partner: UNT Libraries Government Documents Department
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Tests of 16 related airfoils at high speed

Description: From Summary: "In order to provide information that might lead to the development of better propeller section, 13 related symmetrical airfoils were tested in the NACA high-speed wind tunnel for a study of the effect of thickness form on the aerodynamic characteristics. The thickness-form variables studies were the value of the maximum thickness, the position along the chord at which the maximum thickness occurs, and the value of the leading-edge radius. The tests were conducted through the low angle-of-attack range for speeds extending from 35 percent of that of sound to slightly in excess of the speed at which a compressibility burble, or breakdown of flow, occurs. The corresponding Reynolds number range is 350,000 to 750,000."
Date: April 28, 1934
Creator: Stack, John & von Doenhoff, Albert E.
Partner: UNT Libraries Government Documents Department
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The influence of wing setting on the wing load and rotor speed of a PCA-2 autogiro as determined in flight

Description: Flight tests were made on PCA-2 autogiro with wing settings of 2.2 degrees, 0.9 degrees, and -0.5 degrees. The wing load and rotor speed were measured in steady glides. The results obtained show that a wide variation in rotor speed as a function of air speed can be obtained by a suitable adjustment of the wing setting; that by decreasing the wing setting the upper safe flying speed, determined by the decrease is rotor speed, is greatly increased; and that the interference of the wing on the rotor thrust and lift coefficients is negligible.
Date: December 28, 1934
Creator: Wheatley, John B.
Partner: UNT Libraries Government Documents Department
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Wind-Tunnel Interference With Particular Reference to Off-Center Positions of the Wing and to the Downwash at the Tail

Description: "The theory of wind tunnel boundary influence on the downwash from a wing has been extended to provide more complete corrections for application to airplane test data. The first section of the report gives the corrections of the lifting line for wing positions above or below the tunnel center line; the second section shows the manner in which the induced boundary influence changes with distance aft of the lifting line. Values of the boundary corrections are given for off-center positions of the wing in circular, square, 2:1 rectangular, and 2:1 elliptical tunnels" (p. 135).
Date: June 28, 1935
Creator: Silverstein, Abe & White, James A.
Partner: UNT Libraries Government Documents Department
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An Analytical and Experimental Study of the Effect of Periodic Blade Twist on the Thrust, Torque, and Flapping Motion of an Autogiro Rotor

Description: From Summary: "An analysis is made of the influence on autogiro rotor characteristics of a periodic blade twist that varies with the azimuth position of the rotor blade and the results are compared with experimental data. The analysis expresses the influence of this type of twist upon the thrust, torque, and flapping motion of the rotor. The check against experimental data shows that the periodic twist has a pronounced influence on the flapping motion and that this influence is accurately predicted by the analysis. The influence of the twist upon the thrust and torque could be demonstrated only indirectly, but its importance is indicated."
Date: January 28, 1937
Creator: Wheatley, John B.
Partner: UNT Libraries Government Documents Department
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Pressure distribution over a rectangular airfoil with a partial-span split flap

Description: This report presents the results of pressure-distribution tests of a Clark y wing model with a partial-span split flap made to determine the distribution of air loads over both the wing and the flap. The model was used in conjunction with a reflection plane in the NACA 7 by 10 foot wind tunnel. The 20-percent-chord split flap extended over the inboard 60 percent of the semispan. The tests were made at various flap deflections up to 45 degrees and covered a range of angles of attack from zero lift to approximately maximum lift for each deflection.
Date: April 28, 1937
Creator: Wenzinger, Carl J. & Harris, Thomas A.
Partner: UNT Libraries Government Documents Department
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The Crinkling Strength and the Bending Strength of Round Aircraft Tubing

Description: "The upper limit of the column strength of structural members composed of thin material is the maximum axial stress such members can carry when short enough to fail locally, by crinkling. This stress is a function of the mechanical properties of the material and of the geometrical shape of the cross section. The bending strength, as measured by the modulus of rupture, of structural members is also a function of these same variables. Tests were made of round tubes of chromium-molybdenum steel and of duralumin to determine the crinkling strengths and the bending strengths in terms of the specified yield strength and the ratio of diameter to thickness" (p. 387).
Date: March 28, 1938
Creator: Osgood, William R.
Partner: UNT Libraries Government Documents Department
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On some reciprocal relations in the theory of nonstationary flows

Description: In the theory of nonstationary flows about airfoils, the "indicial lift" function ksub1(s) of Wagner and the "alternating lift" function c(k) of Theodorsen have fundamental significance. This paper reports on some interesting relations of the nature of Fourier transforms that exist between these functions. General problems in transient flows about airfoils may be given a unified broad treatment when these functions are employed. Certain approximate results also are reported which are of notable simplicity, and an analogy with transient electrical flows is drawn.
Date: March 28, 1938
Creator: Garrick, I. E.
Partner: UNT Libraries Government Documents Department
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Free-spinning wind-tunnel tests of a low-wing monoplane with systematic changes in wings and tails IV: effect of center-of-gravity location

Description: Eight wings and three tails, covering a wide range of aerodynamic characteristics, were independently ballasted so as to be interchangeable with no change in mass distribution. For each of the 24 resulting wing-tail combinations, observations were made of the steady spin for four control settings and of recoveries for five control manipulations. The results are presented in the form of charts comparing the spin characteristics. The tests are part of a general investigation being made in the NACA free-spinning tunnel to determine the effects of systematic changes in wing and tail arrangement upon the steady-spin and the recovery characteristics of a conventional low-wing monoplane for various load distributions.
Date: March 28, 1939
Creator: Seidman, Oscar & Neihouse, A. I.
Partner: UNT Libraries Government Documents Department
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The design of fins for air-cooled cylinders

Description: From Summary: "An analysis was made to determine the proportions of fins made of aluminum, copper, magnesium, and steel necessary to dissipate maximum quantities of heat for different fin widths, fin weights, and air-flow conditions. The analysis also concerns the determination of the optimum fin proportions when specified limits are placed on the fin dimensions. The calculation of the heat flow in the fins is based on experimentally verified, theoretical equations. The surface heat-transfer coefficients used with this equation were taken from previously reported experiments. In addition to the presentation of fin-design information, this investigation shows that optimum fin dimensions are inappreciably affected by the differences in air flow that are obtained with different air-flow arrangements or by small changes in the length of the air-flow path."
Date: June 28, 1939
Creator: Biermann, Arnold E. & Ellerbrock, Herman H., Jr.
Partner: UNT Libraries Government Documents Department
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Flame Speeds and Energy Considerations for Explosions in a Spherical Bomb

Description: "Simultaneous measurements were made of the speed of flame and the rise in pressure during explosions of mixtures of carbon monoxide, normal heptane, iso-octane, and benzene in a 10-inch spherical bomb with central ignition. From these records, fundamental properties of the explosive mixtures, which are independent of the apparatus, were computed. The transformation velocity, or speed at which flame advances into and transforms the explosive mixture, increases with both the temperature and the pressure of the unburned gas" (p. 39).
Date: September 28, 1939
Creator: Fiock, Ernest F.; Marvin, Charles F., Jr.; Caldwell, Frank R. & Roeder, Carl H.
Partner: UNT Libraries Government Documents Department
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Investigations on the Incompletely Developed Plane Diagonal-Tension Field

Description: This report presents the results of an investigation on the incompletely developed diagonal-tension field. Actual diagonal-tension beams work in an intermediate stage between pure shear and pure diagonal tension; the theory developed by Wagner for diagonal tension is not directly applicable.
Date: March 28, 1940
Creator: Kuhn, Paul
Partner: UNT Libraries Government Documents Department
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Pressure distribution over NACA 23012 airfoil with a slotted and a split flap

Description: A pressure-distribution investigation has been conducted in the NACA 4 by 6-foot vertical wind tunnel to determine the air loads on an NACA 23012 airfoil in combination with a 25.66-percent-chord slotted flap and a 20-percent-chord split flap. Pressures were measured on both the upper and the lower surfaces of the main airfoil and the flaps for several angles of attack and at several flap settings. The data, presented as pressure diagrams and as graphs of the section coefficients for the flap alone and for the airfoil-flap combinations, are applicable to rib and flap design for a combination of a thick airfoil and a slotted or a split flap. The results of previous tests of a NACA 23012 airfoil with a slotted flap are compared with the present results.
Date: May 28, 1940
Creator: Harris, Thomas A. & Lowry, John G.
Partner: UNT Libraries Government Documents Department
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Investigation of the Characteristics of a High-Aspect-Ratio Wing in the Langley 8-Foot High-Speed Tunnel

Description: "An investigation of the characteristics of a wing with an aspect ratio of 9.0 and an NACA 65-210 airfoil section has been made at Mach number up to 0.925. The wing tested has a taper ratio of 2.5:1.0, no twist, dihedral, or sweepback, and 20-percent - chord 37.5-percent-semispan plain ailerons. The results showed that serious changes in the normal-force characteristics occurred when the Mach number was increased above 0.74 at angles of attack between 4 deg. and 10 deg. and above 0.80 at 0 deg. angle of attack" (p. 1).
Date: August 28, 1940
Creator: Whitcomb, Richard T.
Partner: UNT Libraries Government Documents Department
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The Extraction Method of Purification of Uranyl Nitrate

Description: Technical report. Three extractions of a diethyl ether solution of uranyl nitrate with small portions of water are effective in removing rare earths, as is shown by radio-gadolinium and radio-europium tracer experiments. A study of representative ethers, alcohols, ketones, and esters showed that diethyl ether and a mixture of 85% ethyl methyl ketone with 15% xylene are the best solvents for the extraction.
Date: August 28, 1942
Creator: Myers, L. S., Jr.; Anderson, K. C.; Wexler, Sol & Boyd, G. E.
Partner: UNT Libraries Government Documents Department
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