Fire-protective construction on the farm. (open access)

Fire-protective construction on the farm.

Describes the damage that can occur to property and people as a result of fire; and discusses various farm construction projects that prevent a fire or offer protection should a fire occur.
Date: April 1939
Creator: United States. Bureau of Chemistry and Soils.
Object Type: Book
System: The UNT Digital Library
Report on the Agricultural Experiment Stations, 1938 (open access)

Report on the Agricultural Experiment Stations, 1938

Volume provides a summary of the progress of each agricultural experiment station. Also includes statistics and selected studies.
Date: April 1939
Creator: United States. Office of Experiment Stations.
Object Type: Book
System: The UNT Digital Library
Theory of Automatic Control of Airplanes (open access)

Theory of Automatic Control of Airplanes

"Methods of automatically controlling the airplane are reviewed. Equations for the controlled motion including inertia effects of the control are developed and methods of investigating the stability of the resulting fifth and higher order equations are presented. The equations for longitudinal and lateral motion with both ideal and non-ideal controls are developed in dimensionless form in terms of control parameters based on simple dynamic tests of the isolated control unit" (p. 1).
Date: April 1939
Creator: Weiss, Herbert K.
Object Type: Report
System: The UNT Digital Library
Intermittent-flow coefficients of a poppet valve (open access)

Intermittent-flow coefficients of a poppet valve

"Flow coefficients were determined for the inlet valve of a modern air-cooled cylinder during operation of the valve. The cylinder head with valves was mounted on a large tank that could be evacuated. Operating the valve with a rotating cam allowed air to flow through the valve into the evacuated tank. The change of pressure in the tank was a measure of the amount of air flowing though the valve in a given number of cycles. The flow coefficients were determined from the pressure across the valve, the quantity of air flowing, and the valve-lift curve" (p. 1).
Date: April 1939
Creator: Waldron, C. D.
Object Type: Report
System: The UNT Digital Library
Wind-Tunnel Tests of Several Forms of Fixed Wing Slot in Combination With a Slotted Flap on an N.A.C.A. 23012 Airfoil (open access)

Wind-Tunnel Tests of Several Forms of Fixed Wing Slot in Combination With a Slotted Flap on an N.A.C.A. 23012 Airfoil

Note presenting tests of several forms of fixed wing slot in a large-chord NACA 23012 airfoil in the closed-throat 7- by 10-foot wind tunnel. The airfoil extended completely across the test section so that two-dimensional flow was approximated. The data are presented in the form of tables of important aerodynamic characteristics for each slot tested and as curves of section lift, profile-drag, and pitching-moment coefficients.
Date: April 1939
Creator: Bamber, M. J.
Object Type: Report
System: The UNT Digital Library
Propeller Tests to Determine the Effect of Number of Blades at Two Typical Solidities (open access)

Propeller Tests to Determine the Effect of Number of Blades at Two Typical Solidities

"Propellers with equal total blade area, but with different numbers, were tested at Stanford University. The tests show generally that, for equal total blade area, propellers with the larger number of blades absorb the greater power and, provided hubs have equal drag, develop the higher efficiency. It is shown that the differences found are in agreement, qualitatively, with what might be predicted from simple blade-element theory" (p. 1).
Date: April 1939
Creator: Lesley, E. P.
Object Type: Report
System: The UNT Digital Library
Tests of an N.A.C.A. 23012 Airfoil with a slotted deflector flap (open access)

Tests of an N.A.C.A. 23012 Airfoil with a slotted deflector flap

Section aerodynamic characteristics of a large-chord N.A.C.A. 23012 airfoil with a slotted deflector flap were obtained in the N.A.C.A. 7- by 10-foot wind tunnel. The characteristics of an N.A.C.A. slotted flap and of a simple split flap are included for comparison. The slotted deflector flap was found to have a somewhat lower maximum lift coefficient and somewhat higher drag at high lift coefficients than the N.A.C.A. slotted flap. The high drag of the open slot with the deflector flap neutral indicates that the slot should be closed for this condition.
Date: April 1939
Creator: House, R. O.
Object Type: Report
System: The UNT Digital Library
Wind-tunnel investigation of effect of yaw on lateral-stability characteristics 1: four N.A.C.A. 23012 wings of various plan forms with and without dihedral (open access)

Wind-tunnel investigation of effect of yaw on lateral-stability characteristics 1: four N.A.C.A. 23012 wings of various plan forms with and without dihedral

Four N.A.C.A. 23012 wings were tested at several angles of yaw in the N.A.C.A. 7- by 10-foot wind tunnel. All the wings have rounded tips and, in plan form, one is rectangular and the others are tapered 3:1 with various amounts of sweep. Each wing was tested with two amounts of dihedral and with partial-span split flaps. The coefficients of lift, drag, and pitching moment are given for all the models at zero yaw. The coefficients of rolling moment, yawing moment, and side force are given for the rectangular wing at all values of yaw tested. The rate of change in the coefficients with angle of yaw is given in convenient form for stability calculations.
Date: April 1939
Creator: Bamber, M. J. & House, R. O.
Object Type: Report
System: The UNT Digital Library
Contribution to the Theory of the Heated Duct Radiator (open access)

Contribution to the Theory of the Heated Duct Radiator

A method is developed with no neglect of certain factors in mass flow of air and in the drag of the heated radiator, i.e., one under actual operating conditions, as compared with the corresponding values in the cold state, may be simply computed. Although a symmetrical duct radiator has been used to bring out the flow relations, the results apply equally as well to the unsymmetrical radiator shapes usual in airplane construction.
Date: April 1939
Creator: Winter, H.
Object Type: Report
System: The UNT Digital Library
Investigations and Tests in the Towing Basin at Guidonia (open access)

Investigations and Tests in the Towing Basin at Guidonia

The experimental methods at the Guidonia towing basin are discussed including specifications. Some of the components examined are the bridge towing carriage, side towing carriage, catapult installation, and dynamometer systems. Tests were performed on hulls and floats, as well as motor boats and torpedo shaped bodies. Theoretical investigations were also performed to determine pressure distributions on geometrically simple bodies, propagation of small wave motions, and planing and submerged surfaces.
Date: April 1939
Creator: Cremona, C.
Object Type: Report
System: The UNT Digital Library
High-Speed Tests of Radial-Engine Cowlings (open access)

High-Speed Tests of Radial-Engine Cowlings

The drag characteristics of eight radial-engine cowlings have been determined over a wide speed range in the N.A.C.A. 8-foot high-speed wind tunnel. The pressure distribution over all cowlings was measured, to and above the speed of the compressibility burble, as an aid in interpreting the force tests. One-fifth-scale models of radial-engine cowlings on a wing-nacelle combination mere used in the tests.
Date: April 1939
Creator: Robinson, Russell G. & Becker, John V.
Object Type: Report
System: The UNT Digital Library
Cooling on the front of an air-cooled engine cylinder in a conventional engine cowling (open access)

Cooling on the front of an air-cooled engine cylinder in a conventional engine cowling

Measurements were made of the cooling on the fronts of model cylinders in a conventional cowling for cooling in both the ground and the cruising conditions. The mechanisms of front and rear cooling are essentially different. Cooling on the rear baffled part of the cylinders continually increases with increasing fin width. For the front of the cylinder, an optimum fin width was found to exist beyond which an increase in width reduced the heat transfer. The heat transfer coefficient on the front of the cylinders was larger on the side of the cylinder facing the propeller swirl than on the opposite side. This effect became more pronounced as the fin width was increased. These results are introductory to the study of front cooling and show the general effect of several test parameters.
Date: April 5, 1939
Creator: Brevoort, M. J. & Joyner, U. T.
Object Type: Report
System: The UNT Digital Library
Effects of elevator nose shape, gap, balance, and tabs on the aerodynamic characteristics of a horizontal tail surface (open access)

Effects of elevator nose shape, gap, balance, and tabs on the aerodynamic characteristics of a horizontal tail surface

Results are presented showing the effects of gap, elevator, nose shape, balance, cut-out, and tabs on the aerodynamic characteristics of a horizontal tail surface tested in the NACA full-scale tunnel.
Date: April 27, 1939
Creator: Goett, Harry J. & Reeder, J. P.
Object Type: Report
System: The UNT Digital Library
The effect of nacelle-propeller diameter ratio on body interference and on propeller and cooling characteristics (open access)

The effect of nacelle-propeller diameter ratio on body interference and on propeller and cooling characteristics

Report presents the results of an investigation conducted in the NACA 20-foot tunnel to determine the slipstream drag, the body interference, and the cooling characteristics of nacelle-propeller diameter. Four combinations of geometrically similar propellers and nacelles, mounted on standard wing supports, were tested with values of the ratio of nacelle diameter to propeller diameter of 0.25, 0.33, and 0.44.
Date: April 17, 1939
Creator: McHugh, James G. & Derring, Eldridge H.
Object Type: Report
System: The UNT Digital Library
Surface heat-transfer coefficients of finned cylinders (open access)

Surface heat-transfer coefficients of finned cylinders

An investigation to determine and correlate the experimental surface heat-transfer coefficients of finned cylinders with different air-stream cooling arrangements was conducted at the Langley Memorial Aeronautical Laboratory from 1932 to 1938. The investigation covered the determination of the effect of fin width, fin space, fin thickness, and cylinder diameter on the heat transfer. Wind-tunnel tests were made in the free air stream with and without baffles and also with various devices for creating a turbulent air stream. Tests were also made with blower.
Date: April 27, 1939
Creator: Ellerbrock, Herman H., Jr. & Biermann, Arnold E.
Object Type: Report
System: The UNT Digital Library
Experimental Verification of the Theory of Oscillating Airfoils (open access)

Experimental Verification of the Theory of Oscillating Airfoils

"Measurements have been made of the lift on an airfoil in pitching oscillation with a continuous-recording, instantaneous-force balance. The experimental values for the phase difference between the angle of attack and the lift are shown to be in close agreement with theory" (p. 619).
Date: April 24, 1939
Creator: Silverstein, Abe & Joyner, Upshur T.
Object Type: Report
System: The UNT Digital Library
Texas Attorney General Opinion: O-44 (open access)

Texas Attorney General Opinion: O-44

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Gerald Mann, regarding a legal question submitted for clarification; May the Comptroller's Department correct an error in bookkeeping whereby certain moneys were erroneously placed in the General Revenue Fund instead of into the Suspense Fund?
Date: April 11, 1939
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Texas Attorney General Opinion: O-99 (open access)

Texas Attorney General Opinion: O-99

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Gerald Mann, regarding a legal question submitted for clarification: What is proper procedure for selecting trustees following recent election in which three candidates each received 32 votes and a fourth received 31 votes, and one of the candidates receiving 32 votes now agreeing to withdraw in favor of the two who received the same number.
Date: April 4, 1939
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Texas Attorney General Opinion: O-310 (open access)

Texas Attorney General Opinion: O-310

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Gerald Mann, regarding a legal question submitted for clarification;Authority of county auditor to institute suit for benefit of county to recover money paid out under void contract.
Date: April 15, 1939
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Texas Attorney General Opinion: O-346 (open access)

Texas Attorney General Opinion: O-346

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Gerald Mann, regarding a legal question submitted for clarification: Taxability of rolling stock of a truck line that passes through the county.
Date: April 6, 1939
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Texas Attorney General Opinion: O-374 (open access)

Texas Attorney General Opinion: O-374

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Gerald Mann, regarding a legal question submitted for clarification: Is the person whose qualifications are set out qualified to be appointed county auditor?
Date: April 5, 1939
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Texas Attorney General Opinion: O-375 (open access)

Texas Attorney General Opinion: O-375

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Gerald Mann, regarding a legal question submitted for clarification: Distribution of common school district local taxes by county board of trustees.
Date: April 8, 1939
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Texas Attorney General Opinion: O-379 (open access)

Texas Attorney General Opinion: O-379

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Gerald Mann, regarding a legal question submitted for clarification: Authority of a justice of the peace to appoint a deputy or special constable.
Date: April 18, 1939
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Texas Attorney General Opinion: O-403 (open access)

Texas Attorney General Opinion: O-403

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Gerald Mann, regarding a legal question submitted for clarification: Would the inclusion of the phrase "caused by accident" in statutory endorsement forms contravene the quoted portion of the Motor Carrier Act?
Date: April 11, 1939
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History