3,838 Matching Results

Search Results

Results: 1 - 24 next
open access

Genera and Subgenera of Voles and Lemmings

Description: Revision of the genera and subgenera of voles and lemmings with comparison between North American and European.
Date: July 23, 1896
Creator: Miller, Gerrit S. (Gerrit Smith), 1869-1956
Partner: UNT Libraries Government Documents Department
open access

Index Generum Mammalium: a List of the Genera and Families of Mammals

Description: This report consists of three parts: (1) An annotated list of the generic names of mammals; (2) an alphabetical list of the families of mammals, and (3) a classified list of the generic names, arranged by orders and families.
Date: January 23, 1904
Creator: Palmer, T. S.
Partner: UNT Libraries Government Documents Department
open access

The Rice Rats of North America (Genus Oryzomys)

Description: Discusses habits, economic status, morphology, variation, history, and specimens of North American rice rats. Provides a key and descriptions for species and subspecies.
Date: September 23, 1918
Creator: Goldman, Edward A.
Partner: UNT Libraries Government Documents Department
open access

The Lacasa Area, Ranger District North-Central Texas

Description: This document reports the economic geology of the Lacasa area, Ranger district in North-Central Texas, with fieldwork done in April and May of 1919.
Date: December 23, 1921
Creator: Ross, Clarence S.
Partner: UNT Libraries Government Documents Department
open access

Jet Propulsion for Airplanes

Description: This report is a description of a method of propelling airplanes by the reaction of jet propulsion. Air is compressed and mixed with fuel in a combustion chamber, where the mixture burns at constant pressure. The combustion products issue through a nozzle, and the reaction of that of the motor-driven air screw. The computations are outlined and the results given by tables and curves.
Date: March 23, 1922
Creator: Buckingham, Edgar
Partner: UNT Libraries Government Documents Department
open access

Politics of Aviation Fields

Description: In short, the "politics of aviation" lies in a few propositions: the need of having as large a number of fields as possible and of sufficient area; the utilization of the larger part of the existing military fields; the selection of uncultivated or unproductive fields, whenever technical conditions permit; ability to disregard (save in exceptional cases) objections of an agricultural nature.
Date: July 23, 1922
Creator: Vivent, Jacques
Partner: UNT Libraries Government Documents Department
open access

Theory of Determination of Ultra-Radio Frequencies by Standing Waves on Wires

Description: Scientific paper issued by the Bureau of Standards over ultra-radio frequencies. As stated in the abstract, "this paper furnishes the theoretical background for the method of frequency standardization employing short standing waves on parallel wires" (p. 487). This paper includes tables, and illustrations.
Date: June 23, 1924
Creator: Hund, August
Partner: UNT Libraries Government Documents Department
open access

The Measurement of Pressure Through Tubes in Pressure Distribution Tests

Description: "The tests described in this report were made to determine the error caused by using small tubes to connect orifices on the surface of aircraft to central pressure capsules in making pressure distribution tests. Aluminum tubes of 3/16-inch inside diameter were used to determine this error. Lengths from 20 feet to 226 feet and pressures whose maxima varied from 2 inches to 140 inches of water were used. Single-pressure impulses for which the time of rise of pressure from zero to a maximum varied… more
Date: February 23, 1927
Creator: Hemke, Paul E.
Partner: UNT Libraries Government Documents Department
open access

The Comparative Performance of Roots Type Aircraft Engine Superchargers as Affected by Change in Impeller Speed and Displacement

Description: "This report presents the results of tests made on three sizes of roots type aircraft engine superchargers. The impeller contours and diameters of these machines were the same, but the length were 11, 8 1/4, and 4 inches, giving displacements of 0.509, 0.382, and 0.185 cubic foot per impeller revolution. The information obtained serves as a basis for the examination of the individual effects of impeller speed and displacement on performance and of the comparative performance when speed and disp… more
Date: December 23, 1927
Creator: Ware, Marsden & Wilson, Ernest E.
Partner: UNT Libraries Government Documents Department
open access

Maneuverability investigation of the F6C-3 airplane with special flight instruments

Description: "This investigation was made for the purpose of obtaining information on the maneuverability of the F6C-3 airplane. It is the first of a series of similar investigations to be conducted on a number of military airplanes for the purpose of comparing the abilities of these airplanes to maneuver, and also to establish a fund of quantitative data which may be used in formulating standards of comparison for rating the maneuverability of any airplane. A large part of this initial investigation was ne… more
Date: May 23, 1930
Creator: Dearborn, C. H. & Kirschbaum, H. W.
Partner: UNT Libraries Government Documents Department
open access

A New Principle of Sound Frequency Analysis

Description: "In connection with the study of aircraft and propeller noises, the National Advisory Committee for Aeronautics has developed an instrument for sound-frequency analysis which differs fundamentally from previous types, and which, owing to its simplicity of principle, construction, and operation, has proved to be of value in this investigation. The method is based on the well-known fact that the Ohmic loss in an electrical resistance is equal to the sum of the losses of the harmonic components of… more
Date: March 23, 1931
Creator: Theodorsen, Theodore
Partner: UNT Libraries Government Documents Department
open access

Wind-Tunnel Tests of a Clark Y Wing With a Narrow Auxiliary Airfoil in Different Positions

Description: "Aerodynamic force tests were made on a combination of a Clark Y wing and a narrow auxiliary airfoil to find the best location of the auxiliary airfoil with respect to the main wing. The auxiliary was a highly cambered airfoil of medium thickness having a chord 14.5 per cent that of the main wing. It was tested in 141 different positions ahead of, above, and behind the nose portion of the main wing, the range of the test points being extended until the best aerodynamic conditions were covered" … more
Date: February 23, 1932
Creator: Weick, Fred E. & Bamber, Millard J.
Partner: UNT Libraries Government Documents Department
open access

Negative Thrust and Torque Characteristics of an Adjustable-Pitch Metal Propeller

Description: This report presents the results of a series of negative thrust and torque measurements made with a 4 foot diameter model of a conventional aluminum-alloy propeller. The tests were made in the 20-foot propeller-research tunnel of the National Advisory Committee for Aeronautics. The results show that the negative thrust is considerably affected by the shape and size of the body behind the propeller, that the maximum negative thrust increases with decrease in blade-angle setting, and that the dra… more
Date: May 23, 1933
Creator: Hartman, Edwin P.
Partner: UNT Libraries Government Documents Department
open access

The NACA variable-density wind tunnel

Description: This report describes the redesigned variable-density wind tunnel of the National Advisory Committee for Aeronautics; it supersedes a previous report that described the original tunnel. The operation of the balance and the method of testing are explained and the method of correcting and presenting airfoil data is described. A summary of the formulas for predicting the characteristics of finite wings from the airfoil section data as they are usually presented is also given.
Date: November 23, 1933
Creator: Jacobs, Eastman N. & Abbott, Ira H.
Partner: UNT Libraries Government Documents Department
open access

The Weathering of Aluminum Alloy Sheet Materials Used in Aircraft

Description: This report presents the results of an investigation of the corrosion of aluminum alloy sheet materials used in aircraft. It has for its purpose to study the causes of corrosion embrittlement in duralumin-type alloys and the development of methods for its elimination. The report contains results, obtained in an extensive series of weather-exposure tests, which reveal the extent to which the resistance of the materials to corrosion was affected by variable factors in their heat treatment and by … more
Date: March 23, 1934
Creator: Mutchler, Willard
Partner: UNT Libraries Government Documents Department
open access

Improved airplane windshields to provide vision in stormy weather

Description: This report presents the results of wind tunnel tests to determine possible improvements in the design of airplane windshields, particularly with respect to the pilot's vision from the cabin in stormy weather.
Date: May 23, 1934
Creator: Clay, William C.
Partner: UNT Libraries Government Documents Department
open access

Wind-tunnel research comparing lateral control devices particularly at high angles of attack 13: auxiliary airfoils used as external ailerons

Description: This is the thirteenth report on a series of systematic tests comparing lateral control devices with particular reference to their effectiveness at high angles of attack. The present wind tunnel tests were made to determine the most feasible locations for lateral control surfaces mounted externally to a rectangular Clark y wing.
Date: July 23, 1934
Creator: Weick, Fred E. & Noyes, Richard W.
Partner: UNT Libraries Government Documents Department
open access

Downwash and Wake Behind Plain and Flapped Airfoils

Description: "Extensive experimental measurements have been made of the downwash angles and the wake characteristics behind airfoils with and without flaps and the data have been analyzed and correlated with the theory. A detailed study was made of the errors involved in applying lifting-line theory, such as the effects of a finite wing chord, the rolling-up of the trailing vortex sheet, and the wake. The downwash angles, as computed from the theoretical span load distribution by means of the Biot-Savart eq… more
Date: June 23, 1938
Creator: Silverstein, Abe; Katzoff, S. & Bullivant, W. Kenneth
Partner: UNT Libraries Government Documents Department
open access

The Pack Method for Compressive Tests of Thin Specimens of Materials Used in Thin-Wall Structures

Description: "The strength of modern lightweight thin-wall structures is generally limited by the strength of the compression members. An adequate design of these members requires a knowledge of the compressive stress-strain graph of the thin-wall material. The "pack" method was developed at the National Bureau of Standards with the support of the National Advisory Committee for Aeronautics to make possible a determination of compressive stress-strain graphs for such material" (p. 133).
Date: August 23, 1938
Creator: Aitchison, C. S. & Tuckerman, L. B.
Partner: UNT Libraries Government Documents Department
open access

Calculation of the Aerodynamic Characteristics of Tapered Wings With Partial-Span Flaps

Description: "Factors derived from wing theory are presented. By means of these factors, the angle of zero lift, the lift-curve slope, the pitching moment, the aerodynamic-center position, and the induced drag of tapered wings with partial-span flaps may be calculated. The factors are given for wings of aspect ratios 6 and 10 , of taper ratios from 0.25 to 1.00, and with flaps of various length. An example is presented of the method of application of the factors. Fair agreement with experimental results is … more
Date: January 23, 1939
Creator: Pearson, Henry A. & Anderson, Raymond F.
Partner: UNT Libraries Government Documents Department
open access

Tensile Elastic Properties of Typical Stainless Steels and Nonferrous Metals as Affected by Plastic Deformation and by Heat Treatment

Description: A general discussion is given of the relationships between stress, strain, and permanent set. From stress-set curves are derived proof stresses based on five different percentages of permanent set. The influence of prior plastic extension on these values is illustrated and discussed. A discussion is given of the influence of work-hardening, rest interval, and internal stress on the form of the proof stress-extension curve.
Date: February 23, 1940
Creator: McAdam, D. J., Jr. & Mebs, R. W.
Partner: UNT Libraries Government Documents Department
open access

Production of DsSub 2$O for Use in the Fission of Uranium

Description: Brief discussions of experimental methods, kinetics, and the catalysts used in the production of D{sub 2}O are presented (J.E.D.)
Date: June 23, 1941
Creator: Urey, H. C.; Grosse, A. V. & Walden, G.
Partner: UNT Libraries Government Documents Department
Back to Top of Screen