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Cattle-Fever Ticks and Methods of Eradication

Description: Revised edition. This bulletin discusses the cattle-fever tick and methods for controlling it. Possible methods include dipping, pasture rotation, and arsenical dips. The life history of the tick is also discussed and instructions for constructing a concrete vat are given.
Date: 1940
Creator: Ellenberger, W. P. & Chapin, Robert M.
Item Type: Refine your search to only Pamphlet
open access

The Cause of Welding Cracks in Aircraft Steels

Description: The discussion in this article refers to gas welding of thin-walled parts of up to about 3 mm thickness. It was proven that by restricting the sulphur, carbon, and phosphorous content, and by electric-furnace production of the steel, it was possible in a short time to remove this defect. Weld hardness - i.e., martensite formation and hardness of the overheated zone - has no connection with the tendency to weld-crack development. Si, Cr, Mo, or V content has no appreciable effect, while increase… more
Date: October 1940
Creator: Müller, J.
Item Type: Refine your search to only Report
open access

Celery growing.

Description: A guide to commercial celery-growing, with brief instructions for growing celery in home gardens. Includes descriptions of celery diseases and insect pests.
Date: 1940
Creator: Beattie, W. R. (William Renwick), b. 1870
Item Type: Refine your search to only Book
open access

Chordwise Load Distribution of a Simple Rectangular Wing

Description: The chordwise distribution theory was taken over from the theory of the infinite wing. Since in this work a series expansion in b/t was used, the computation converges only for large aspect ratios. In this paper a useful approximate solution will be found also for wings with large chord - i.e., small aspect ratio.
Date: December 1940
Creator: Wieghardt, Karl
Item Type: Refine your search to only Report
open access

Coal-Mine Accidents in the United States, 1937

Description: Report compiled by the U.S. Bureau of Mines including statistics on fatal and non-fatal accidents in coal mines located in the United States as well as data regarding the various operations (e.g., number of miners employed and average production). The information is organized into tables for comparison and the text draws some overall conclusions in the summary.
Date: 1940
Creator: Adams, William W.; Geyer, L. E. & Parry, M. G.
Item Type: Refine your search to only Report
open access

Comparison of Three Exit-Area Control Devices on an N.A.C.A. Cowling, Special Report

Description: "Adjustable cowling flaps, an adjustable-length cowling skirt, and a bottom opening with adjustable flap were tested as means of controlling the rate of cooling-air flow through an air-cooled radial-engine cowling. The devices were tested in the NACA 20-foot tunnel on a model wing-nacelle-propeller combination, through an airspeed range of 20 to 80 miles per hour, and with the propeller blade angle set 23 degrees at 0.75 of the tip radius. The resistance of the engine to air flow through the co… more
Date: May 1940
Creator: McHugh, James G.
Item Type: Refine your search to only Report
open access

Consideration of Auxiliary Jet Propulsion for Assisting Take-Off

Description: Report presenting an analysis and simple method to help solve the problem of assisting the take-off of an airplane by means of auxiliary jet propulsion by determining the jet thrust and weight of jet fuel required to provide a desired reduction in take-off distance or increase in pay load or fuel load for a fixed take-off distance. The use of previous experimental work to verify the analysis is also provided.
Date: May 1940
Creator: Turner, L. Richard
Item Type: Refine your search to only Report
open access

Constant-Pressure Blowers

Description: "The conventional axial blowers operate on the high-pressure principle. One drawback of this type of blower is the relatively low pressure head, which one attempts to overcome with axial blowers producing very high pressure at a given circumferential speed. The Schicht constant-pressure blower affords pressure ratios considerably higher than those of axial blowers of conventional design with approximately the same efficiency" (p. 1).
Date: January 1940
Creator: Sörensen, E.
Item Type: Refine your search to only Report
open access

Corn culture.

Description: A general guide to growing corn crops in the United States, including selection, land preparation, planting, culture, and insect and disease control.
Date: 1940
Creator: Richey, Frederick D. (Frederick David), b. 1884
Item Type: Refine your search to only Book
open access

Corrections on the Thermometer Reading in an Air Stream

Description: A method is described for checking a correction formula, based partly on theoretical considerations, for adiabatic compression and friction in flight tests and determining the value of the constant. It is necessary to apply a threefold correction to each thermometer reading. They are a correction for adiabatic compression, friction and for time lag.
Date: October 1940
Creator: Van der Maas, H. J. & Wynia, S.
Item Type: Refine your search to only Report
open access

Correlation of knocking characteristics of fuels in an engine having a hemispherical combustion chamber

Description: From Summary: "Data are presented to show the effects of inlet-air pressure, inlet-air temperature, and compression ratio on the maximum permissible performance obtained with having a hemispherical-dome combustion chamber. The five aircraft-engine fuels used have octane numbers varying from 90 to 100 plus 2 ml of tetraethyl lead per gallon. The data were obtained on a 5 1/4-inch by 4 3/4-inch liquid-cooled engine operating at 2,500 r.p.m. The compression ratio was varied from 6.0 to 8.9. The in… more
Date: July 1940
Creator: Rothrock, A. M. & Biermann, Arnold E.
Item Type: Refine your search to only Report
open access

Creep Strength of Stabilized Wrought-Aluminum Alloys

Description: Rohn-type equipment has been mounted on rubber blocks, for the purpose of damping the vibrations of the ground and of rendering the plastic yielding of the test bars less subject to outside interferences. New equipment also included three shockproof creep-testing machines with the Martens mirror instruments for recording the strain curve of the fatigue-tested specimens.
Date: November 1940
Creator: Müller, W.
Item Type: Refine your search to only Report
open access

Cyclic stress-strain studies of metals in torsion

Description: Report presenting cyclic torsion tests made to determine the effects of varying amounts of torsional overstrain on the shape of the shearing stress-strain diagrams of aluminum alloy 17ST, mild steel, wrought iron, copper, brass, and magnesium alloy AX57S. Results regarding the tensile, compressive, and shear properties are provided.
Date: December 1940
Creator: Paul, D. A. & Moore, R. L.
Item Type: Refine your search to only Report
open access

Damping formulas and experimental values of damping in flutter models

Description: The problem of determining values of structural damping for use in flutter calculations is discussed. The concept of equivalent viscous damping is reviewed and its relation to the structural damping coefficient g introduced in NACA Technical Report No. 685 is shown. The theory of normal modes is reviewed and a number of methods are described for separating the motions associated with different modes. Equations are developed for use in evaluating the damping parameters from experimental data. Ex… more
Date: February 1940
Creator: Coleman, Robert P.
Item Type: Refine your search to only Report
open access

Design Charts Relating to the Stalling of Tapered Wings

Description: An aid in airplane design, charts have been prepared to show the effects of wing taper, thickness ratio, and Reynolds number on the spanwise location of the initial stalling point. Means of improving poor stalling characteristics resulting from certain combinations of the variables have also been considered; additional figures illustrate the influence of camber increase to the wing tips, washout, central sharp leading edges, and wing-tip slots on the stalling characteristics. Data are included … more
Date: January 18, 1940
Creator: Soulé, H. A. & Anderson, R. F.
Item Type: Refine your search to only Report
open access

The Design of Cooling Ducts With Special Reference to the Boundary Layer at the Inlet

Description: "A study has been made of underslung cooling ducts with special references to the problems presented by the boundary layer on the fuselage skin. It was found that good flow can be obtained in such ducts by (1) making the inlet opening of such size that the mean inlet velocity is about 0.6 the free-stream velocity and (2) providing vanes behind as well as ahead of the radiator. Tables to facilitate design are included, together with an example " (p. 1).
Date: December 1940
Creator: Katzoff, S.
Item Type: Refine your search to only Report
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