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  Partner: UNT Libraries Government Documents Department
 Decade: 1940-1949
 Year: 1940
Celery growing.

Celery growing.

Date: 1940
Creator: Beattie, W. R. (William Renwick), b. 1870.
Description: A guide to commercial celery-growing, with brief instructions for growing celery in home gardens. Includes descriptions of celery diseases and insect pests.
Contributing Partner: UNT Libraries Government Documents Department
Chart for critical compressive stress of flat rectangular plates

Chart for critical compressive stress of flat rectangular plates

Date: August 1, 1940
Creator: Hill, H N
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Chordwise load distribution of a simple rectangular wing

Chordwise load distribution of a simple rectangular wing

Date: December 1, 1940
Creator: Wieghardt, Karl
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.
Contributing Partner: UNT Libraries Government Documents Department
Clothes moths.

Clothes moths.

Date: January 1940
Creator: Back, E. A. (Ernest Adna), 1886-
Description: Describes the life cycle and characteristics of clothes moths, and methods for their control.
Contributing Partner: UNT Libraries Government Documents Department
Coal-Mine Accidents in the United States, 1937

Coal-Mine Accidents in the United States, 1937

Date: 1940
Creator: Adams, William W.; Geyer, L. E. & Parry, M. G.
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.
Contributing Partner: UNT Libraries Government Documents Department
Comparison of Three Exit-Area Control Devices on an N.A.C.A. Cowling, Special Report

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

Date: May 1, 1940
Creator: McHugh, James G.
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 cowling was simulated by a perforated plate. The results indicated that the adjustable cowling flap and the bottom opening with adjustable flap were about equally effective on the basis of pressure drop obtainable and that both were more effective means of increasing the pressure drop through the cowling than the adjustable-length skirt. At conditions of equal cooling-air flow, the net efficiency obtained with the adjustable cowling flaps and the adjustable-length cowling skirt was about 1% greater than the net efficiency obtained with the bottom opening with adjustable flap.
Contributing Partner: UNT Libraries Government Documents Department
Consideration of auxiliary jet propulsion for assisting take-off

Consideration of auxiliary jet propulsion for assisting take-off

Date: May 1, 1940
Creator: Turner, L Richard
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Constant-pressure blowers

Constant-pressure blowers

Date: January 1, 1940
Creator: Sorensen, E
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.
Contributing Partner: UNT Libraries Government Documents Department
Construction of chimneys and fireplaces.

Construction of chimneys and fireplaces.

Date: 1940
Creator: United States. Bureau of Agricultural Engineering.
Description: Describes the principles of chimney and fireplace construction. Provides schematics.
Contributing Partner: UNT Libraries Government Documents Department
Corn culture.

Corn culture.

Date: 1940
Creator: Richey, Frederick D. (Frederick David), b. 1884.
Description: A general guide to growing corn crops in the United States, including selection, land preparation, planting, culture, and insect and disease control.
Contributing Partner: UNT Libraries Government Documents Department
Corrections on the thermometer reading in an air stream

Corrections on the thermometer reading in an air stream

Date: October 1, 1940
Creator: Van Der Maas, H J & Wynia, S
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.
Contributing Partner: UNT Libraries Government Documents Department
Correlation Index to Aid in Interpreting Crude-Oil Analyses

Correlation Index to Aid in Interpreting Crude-Oil Analyses

Date: 1940
Creator: Smith, Harold M.
Description: Report issued by the Bureau of Mines discussing the correlation index used for analyses of crude oils. The correlation index is presented and described in detail. This report includes tables, and illustrations.
Contributing Partner: UNT Libraries Government Documents Department
Correlation of cooling data from an air-cooled cylinder and several multicylinder engines

Correlation of cooling data from an air-cooled cylinder and several multicylinder engines

Date: January 1, 1940
Creator: Pinkel, Benjamin & Ellerbrock, Herman H , Jr
Description: The theory of engine-cylinder cooling developed in a previous report was further substantiated by data obtained on a cylinder from a Wright r-1820-g engine. Equations are presented for the average head and barrel temperatures of this cylinder as functions of the engine and the cooling conditions. These equations are utilized to calculate the variation in cylinder temperature with altitude for level flight and climb. A method is presented for correlating average head and barrel temperatures and temperatures at individual points on the head and the barrel obtained on the test stand and in flight. The method is applied to the correlation and the comparison of data obtained on a number of service engines. Data are presented showing the variation of cylinder temperature with time when the power and the cooling pressure drop are suddenly changed.
Contributing Partner: UNT Libraries Government Documents Department
Correlation of knocking characteristics of fuels in an engine having a hemispherical combustion chamber

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

Date: July 1, 1940
Creator: Rothrock, A M & Biermann, Arnold E
Description: 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 inlet-air temperature was varied from 110 to 310 F. For each set of conditions, the inlet-air pressure was increased until audible knock occurred and then reduced 2 inches of mercury before data were recorded. The results for each fuel can be correlated by plotting the calculated end-gas density factor against the calculated end-gas temperature. Measurements of spark-plugs, cutting off the switch to one spark plug lowered the electrode temperature of that plug from a value of 1,365 F to a value of 957 F. The results indicate that the surface temperatures of combustion-chamber areas which become new sources of ignition markedly increase after ignition.
Contributing Partner: UNT Libraries Government Documents Department
Cottonseed treatment.

Cottonseed treatment.

Date: March 1940
Creator: Haskell, R. J. & Barker, Henry D.
Description: Describes the methods of treating cottonseed to prevent disease or decay.
Contributing Partner: UNT Libraries Government Documents Department
Creep strength of stabilized wrought-aluminum alloys

Creep strength of stabilized wrought-aluminum alloys

Date: November 1, 1940
Creator: Muller, W
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.
Contributing Partner: UNT Libraries Government Documents Department
Cyclic stress-strain studies of metals in torsion

Cyclic stress-strain studies of metals in torsion

Date: December 1, 1940
Creator: Paul, D A & Moore, R L
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Damping formulas and experimental values of damping in flutter models

Damping formulas and experimental values of damping in flutter models

Date: February 1, 1940
Creator: Coleman, Robert P
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. Experimental results of measurements of damping in several flutter models are presented.
Contributing Partner: UNT Libraries Government Documents Department
Deciduous-fruit improvement through tree-performance records.

Deciduous-fruit improvement through tree-performance records.

Date: 1940
Creator: Shamel, A. D. (Archibald Dixon), 1878- & Pomeroy, C. S. (Carl Stone), 1882-
Description: Discusses commercial production of deciduous fruits based on the culture of established, profitable varieties. Describes the use of individual tree-records, the negative impacts of undesirable trees, and how to locate and isolate them.
Contributing Partner: UNT Libraries Government Documents Department
Design charts relating to the stalling of tapered wings

Design charts relating to the stalling of tapered wings

Date: January 1, 1940
Creator: Soule, H A & Anderson, R F
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 from which the drag increases resulting from the use of these means can be computed. The application of the data to a specific problem is illustrated by an example.
Contributing Partner: UNT Libraries Government Documents Department
The design of cooling ducts with special reference to the boundary layer at the inlet

The design of cooling ducts with special reference to the boundary layer at the inlet

Date: December 1, 1940
Creator: Katzoff, S
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Determination of ground effect from tests of a glider in towed flight

Determination of ground effect from tests of a glider in towed flight

Date: January 1, 1940
Creator: Wetmore, J W & Turner, L I , Jr
Description: Report presents the results of an investigation made to find the effect of ground on the aerodynamic characteristics of a Franklin PS-2 glider. The lift, the drag, and the angle of attack of the glider in towed flight were determined at several heights from 0.14 to 1.19 span lengths and at various speeds for each height. Two wing arrangements were tested: the plain wing, and the wing with a nearly full-span 30-percent-chord split flap deflected 45 degrees. The experimental results for the plain wing were in good agreement with theoretical values calculated by the method of Wieselsberger for both the angle of attack and the drag coefficient at a height of 0.21 span length; Tani's refinements of the theory had a practically negligible effect on the computed values in this case.
Contributing Partner: UNT Libraries Government Documents Department
The development of electrical strain gages

The development of electrical strain gages

Date: January 1, 1940
Creator: De Forest, A V & Leaderman, H
Description: The design, construction, and properties of an electrical-resistance strain gage consisting of fine wires molded in a laminated plastic are described. The properties of such gages are discussed and also the problems of molding of wires in plastic materials, temperature compensation, and cementing and removal of the gages. Further work to be carried out on the strain gage, together with instrument problems, is discussed.
Contributing Partner: UNT Libraries Government Documents Department
DFS dive-control brakes for gliders and airplanes ; and, Analytical study of the drag of the DFS dive-control brake

DFS dive-control brakes for gliders and airplanes ; and, Analytical study of the drag of the DFS dive-control brake

Date: January 1, 1940
Creator: Jacobs, Hans & Wanner, Adolf
Description: These two reports are surveys on the progress and present state of development of dive-control flaps for gliders and airplanes. The second article describes how on the basis of wind tunnel and free-flight tests, the drag increase on brake flaps of the type DFS, can be predicted. Pressure records confirm a two-dimensional load distribution along the brake-flap surface Aerodynamically, the location of the brake flaps along the span is of importance for reasons of avoidance of vibration and oscillation phenomena on control and tail surfaces; statically, because of the magnitude of the frontal drag in diving with respect to the bending moments, which may become decisive for the dimensions of the wing attachment and for the wing covering.
Contributing Partner: UNT Libraries Government Documents Department