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Harvest Mites, or "Chiggers"

Description: This report discusses a type of harvest mite known colloquially as the "chigger" or "red bug." Although these creatures are arachnids, they are not ticks and do not cause serious injury to humans or livestock. The life cycle of the harvest mite, treatment for mite attacks, and methods for destroying the mite are discussed.
Date: 1915
Creator: Chittenden, F. H. (Frank Hurlbut), 1858-1929
Partner: UNT Libraries Government Documents Department

Skin frictional resistance of plane surfaces in air: Abstract of recent German tests, with notes

Description: Given here is the most recent research on skin frictional resistance of plane surfaces in air that was conducted by Dr. Wieselsberger under the direction of Dr. Prandtl of Gottingen University. In all, 16 models were tested. These were divided into four groups, as follows: 1) cloth, in the original condition; 2) cloth, with the nap singed off; 3) cloth, with three coats of dope; and 4) cloth, with six coats of dope. Each group consisted of four models of uniform width, 1 meter, and of lengths of 0.5, 1.0, 1.5, and 2.0 meters.
Date: July 1922
Creator: Diehl, W. S.
Partner: UNT Libraries Government Documents Department

Comparison of Three Methods for Calculating the Compressive Strength of Flat and Slightly Curved Sheet and Stiffener Combinations

Description: "This report gives a comparison of the accuracy of the three methods for calculating the compressive strength of flat sheet and stiffener combinations such as occur in stressed-skin or monocoque structures for aircraft. Of the three methods based upon various assumptions with regard to the interaction of sheet and stiffener, the method based upon mutual action of the stiffener and an effective width as a column gave the best agreement with the results of the tests. An investigation of the effect of small curvature resulted in the conclusion that the compressive strength of the curved panels is, for all practical purposes, equal to the strength of flat panels except for thick sheet where non-uniform curvature throughout the length may cause the strength of the curved panel to be 10 to 15 percent less than that of a corresponding flat panel" (p. 1).
Date: March 1933
Creator: Lundquist, Eugene E.
Partner: UNT Libraries Government Documents Department

Pressure and Frictional Resistance of a Cylinder at Reynolds Numbers 5,000 to 40,000

Description: This report presents the results of a series of free-jet measurements to determine the pure frictional resistance of a cylinder from the difference between total resistance and pressure at Reynolds Numbers 5,000 to 40,700. The skin friction is 5 percent of the total resistance at Re = 5,000, and had dropped to 2 percent at Re = 40,000, which supports Thom's theory.
Date: July 1933
Creator: Schiller, L. & Linke, W.
Partner: UNT Libraries Government Documents Department

On the Theory of Laminar Boundary Layers Involving Separation

Description: "This paper presents a mathematical discussion of the laminar boundary layer, which was developed with a view of facilitating the investigation of those boundary layers in particular for which the phenomenon of separation occurs. The treatment starts with a slight modification of the form of the boundary layer equation first published by Von Mises. Two approximate solutions of this equation are found, one of which is exact at the outer edge of the boundary layer while the other is exact at the wall" (p. 541).
Date: May 22, 1934
Creator: Von Karman, Theodore & Millikan, C. B.
Partner: UNT Libraries Government Documents Department

Contributions to the Theory of Incomplete Tension Bay

Description: The present report offers an approximate theory for the stress and deformation condition after buckling of the skin in reinforced panels and shells loaded in simple shear and compression and under combined stresses. The theory presents a unified scheme for stresses of these types. It is based upon the concept of a nonuniform stress distribution in the metal panel and its marked power of resistance against compressive stresses ("incomplete" tension bay).
Date: July 1937
Creator: Schapitz, E.
Partner: UNT Libraries Government Documents Department

Flutter tests of modified SB2U model in 16-foot tunnel

Description: Report presenting testing of the flutter characteristics of the SB2U model conducted after the model had been modified to lower its flutter speed. The model was tested to destruction and the flutter speed was measured throughout.
Date: August 1943
Creator: Theodorsen, Theodore; Coleman, R. P. & Smith, N. H.
Partner: UNT Libraries Government Documents Department

Critical shear stress of an infinitely long flat plate with equal elastic restraints against rotation along the parallel edges

Description: Report presenting a chart for the values of the coefficient in the formula for the critical shear stress at which buckling may be expected to occur in an infinitely long flat plate with parallel edges. An approximate method for the evaluation of the critical shear stress when the elastic restraints on the two parallel edges are not equal is also presented.
Date: November 1943
Creator: Stowell, Elbridge Z.
Partner: UNT Libraries Government Documents Department

Comparison of an approximate and an exact method of shear-lag analysis

Description: Report presenting comparisons between the approximate substitute single-stringer method of shear-lag analysis and the exact solutions, which indicate that for beams of practical proportions the approximate method yields a value for the maximum root stress that exceeds the value obtained by use of the exact solution by less than 10 percent.
Date: January 1944
Creator: Duberg, John E.
Partner: UNT Libraries Government Documents Department

Summary of research of the section on pharmacology. Progress report for December 1944

Description: Various studies relating the biological and behavioral effect of several uranium fluorides and chlorides as well as fluorine and oxyflourides are related. Most of these studies involved rats, guinea pigs, rabbits or dogs. Route of administration included inhalation, ingestion, or application to the skin.
Date: December 31, 1944
Creator: Hodge, H.C.
Partner: UNT Libraries Government Documents Department

High-Speed Investigation of Skin Wrinkles on Two NACA Airfoils

Description: Note presenting an investigation of the effects on the aerodynamic characteristics of skin wrinkles on the forward part of the upper surface of two NACA airfoils. The results showed that no appreciable change in normal-force or pitching-moment characteristics over the range of Mach numbers tested was noted. The drag was greater on the wrinkled sections than the smooth sections, however.
Date: August 1946
Creator: Robinson, Harold L.
Partner: UNT Libraries Government Documents Department

Protective measures for personnel

Description: This document addresses radiation protection concerns for workers in the experimental laboratories and production plants where nuclear fission piles are being used. A broad in-depth discussion is provided based with the experiences gained in the Manhattan Project and being applied to contemporary activities. Discussion is thorough and encompasses control of external irradiations including alpha, beta, gamma, and neutron radiations; and control of radioactivity within the body by control of inhalation, ingestion, and entrance through skin or wounds. General measures for the control of radiation hazards is addressed by provision of clothing and waste disposal. An Appendix 1 is entitled General Rules and Procedures Concerning Activity Hazards.
Date: December 13, 1946
Creator: Nickson, J.J.
Partner: UNT Libraries Government Documents Department

Stresses around rectangular cut-outs with reinforced coaming stringers

Description: Strain measurements and strength tests were made on six skin-stringer panels under axial load. Three of these panels had short rectangular cut-outs, and three a long one. The width of the cut-out was about one-half of the width of the panel. Three types of coating stringers were used: without reinforcement, with riveted-up reinforcement, or with integral reinforcement. The strain measurements were found to be in good agreement with a previously published theory adapted where necessary by making overlapping assumptions.
Date: January 1947
Creator: Kuhn, Paul; Rafel, Norman & Griffith, George E.
Partner: UNT Libraries Government Documents Department

Experimental Investigation of the Stress Distribution Around Reinforced Circular Cut-Outs in Skin Stringer Panels Under Axial Loads

Description: Note presenting results of strain surveys around four reinforced circular cut-outs successively made in an axially loaded skin-stringer tension panel. Curves are presented which show the distribution of stringer and shear stresses in the panel and bending stresses in the reinforcing rings.
Date: March 1947
Creator: Farb, Daniel
Partner: UNT Libraries Government Documents Department

A Study of Skin Temperatures of Conical Bodies in Supersonic Flight

Description: Memorandum presenting a comparison between the time history of skin temperature measured on the nose of a V-2 and the temperature computed using Eber's experimental relation for heat-transfer coefficients for conical bodies under supersonic conditions. A general method developed for making skin-temperature calculations is used to compute the variation of skin temperature with time for a wide range of values of the pertinent parameters. Results regarding the validity of skin-temperature calculations, ranges of skin temperature, and skin temperatures for a typical supersonic airplane are provided.
Date: January 29, 1948
Creator: Huston, Wilber B.; Warfield, Calvin N. & Stone, Anna Z.
Partner: UNT Libraries Government Documents Department

Determination of Transient Skin Temperature of Conical Bodies During Short-Time, High-Speed Flight

Description: Note presenting a short and simple method for the determination of transient skin temperature of conical bodies during short-time, high-speed flight. A differential equation is presented for this purpose, which gives the fundamental relations between the transient skin temperature and flight history. Results regarding flights at constant altitude and general flight conditions are given, and the calculated skin temperature for a V-2 missile is in good agreement with the measured data.
Date: October 1948
Creator: Lo, Hsu
Partner: UNT Libraries Government Documents Department

A Study of Skin Temperatures of Conical Bodies in Supersonic Flight

Description: Note presenting a comparison between the time history of skin temperature measured on the nose of a V-2 missile and the time history of the temperature computed by the use of Eber's experimental relation for heat-transfer coefficients for conical bodies under supersonic conditions. A general method developed for making such skin-temperature calculations is used to compute the variation of skin temperature with time for a wide range of values of the pertinent parameters.
Date: October 1948
Creator: Huston, Wilber B.; Warfield, Calvin N. & Stone, Anna Z.
Partner: UNT Libraries Government Documents Department

Direct-reading design charts for 24S-T aluminum-alloy flat compression panels having longitudinal straight-web Y-section stiffeners

Description: "Direct-reading design charts are presented for 24S-T aluminum-alloy flat compression panels having longitudinal straight-web Y-section stiffeners. These charts make possible the direct determination of the stress and all the panel proportions required to carry a given intensity of loading with a given skin thickness and effective length of panel" (p. 1).
Date: January 1949
Creator: Dow, Norris F.; Hubka, Ralph E. & Roberts, William M.
Partner: UNT Libraries Government Documents Department

Elastic Buckling of Outstanding Flanges Clamped at One Edge and Reinforced by Bulbs at Other Edge

Description: Note presenting the compressive buckling stress of outstanding flanges reinforced by bulbs, which was computed by the strain-energy method for flanges with 10 shapes and a range of lengths. The results were checked for some cases by computations based on a differential-equation method. The results were analyzed to determine which shape of flange gave the greatest support to the structure to which it was attached.
Date: October 1949
Creator: Goodman, Stanley
Partner: UNT Libraries Government Documents Department