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FCC Reports, Volume 5, November 16, 1937 to June 30, 1938

Description: Biweekly, comprehensive compilation of decisions, reports, public notices, and other documents of the U.S. Federal Communications Commission.
Date: 1939
Creator: United States. Federal Communications Commission.
Partner: UNT Libraries Government Documents Department

Subsurface Geology and Oil and Gas Resources of Osage County, Oklahoma: Part 2. Townships 22 and 23 North Ranges 8 and 9 East

Description: This report is part of a series describing the structural features, the character of the oil- and gas-producing beds, and the localities where additional oil and gas may be found in parts of Osage County, Oklahoma. This part discusses the geology and resources in the southeastern part of the county, around Hominy, Oklahoma.
Date: 1939
Creator: Kirk, Charles Townsend; Jenkins, H. D.; Leatherock, Otto; Dillard, W. R.; Kennedy, L. E. & Bass, N. Wood
Partner: UNT Libraries Government Documents Department

Geology and Fuel Resources of the Southern Part of the Oklahoma Coal Field: Part 4. the Howe-Wilburton District, Latimer and Le Flore Counties

Description: From abstract: The Howe-Wilburton district is a narrow area of about 540 square miles that extends westward from the Arkansas State line for about 60 miles across Latimer and Le Flore Counties, Okla. It lies in the southern part of the Arkansas Valley physiographic province and is a part of the large Arkansas-Oklahoma coal field.
Date: 1939
Creator: Hendricks, Thomas Andrews
Partner: UNT Libraries Government Documents Department

Mineral Industry of Alaska in 1938

Description: From introduction: The presentation of a yearly record of the Alaska mineral industry is a continuing service that has been rendered by the Geological Survey from almost the earliest years of extensive mining in Alaska, and the present report, for 1938, is the thirty-fifth of this series. 2 Such a record, especially when supplemented by the statistics for the preceding years, not only affords an authoritative summary of current 'and past conditions but also indicates trends that are of significance in suggesting the lines along which future developments of the industry are likely to proceed. These reports therefore serve miners, prospectors, and businessmen concerned with Alaska affairs as useful historical records, statements of contemporary conditions, and starting points on which some conjectures concerning future operations may be predicated.
Date: 1939
Creator: Smith, Philip Sidney
Partner: UNT Libraries Government Documents Department

Subsurface Geology and Oil and Gas Resources of Osage County, Oklahoma: Part 3. Townships 24 and 25 North Ranges 8 and 9 East

Description: This report is part of a series describing the structural features, the character of the oil- and gas-producing beds, and the localities where additional oil and gas may be found in parts of Osage County, Oklahoma. This part discusses the geology and resources in the center part of the county.
Date: 1939
Creator: Bass, N. Wood; Kennedy, L. E.; Conley, J. N. & Hengst, J. H.
Partner: UNT Libraries Government Documents Department

Spirit Leveling in South Carolina: Part 1. Northern South Carolina, 1896-1938

Description: From introduction: report.-This bulletin, which is published in two parts, contains the complete results of all spirit leveling done in South Carolina by the Geological Survey of the United States Department of the Interior, including those heretofore published.1 The 34th parallel of latitude, passing through Columbia, serves to divide the State into two sections, each of which is represented by one of the parts of the bulletin. Part 1 deals with the section lying north of the 34th parallel, designated as northern South Carolina, and part 2 deals with the section lying south of that parallel, designated as southern South Carolina.
Date: 1939
Creator: Staack, J. G.
Partner: UNT Libraries Government Documents Department

Torsional stability of aluminum alloy seamless tubing

Description: Torsion tests were made on 51ST aluminum-alloy seamless tubes having diameter-to-thickness ratios of from 77 to 139 and length-to-diameter ratios of from 1 to 60. The torsional strengths developed in the tubes which failed elastically (all tubes having lengths greater than 2 to 6 times the diameter) were in most cases within 10 percent of the value indicated by the theories of Donnel, Timoshenko, and Sturm, assuming a condition of simply supported ends.
Date: March 1939
Creator: Moore, R. L. & Paul, D. A.
Partner: UNT Libraries Government Documents Department

The frequency of torsional vibration of a tapered beam

Description: A solution for the equation of torsional vibration of tapered beams has been found in terms of Bessel functions for beams satisfying the following conditions: (a) the cross sections along the span are similar in shape; and (b) the torsional stiffness of a section can be expressed as a power of a linear function of distance along the span. The method of applying the analysis to actual cases has been described. Charts are given from which numerical values can be immediately obtained for most cases of practical importance. The theoretical values of the frequency ratio have been experimentally checked on five beams having different amounts of taper.
Date: March 1, 1939
Creator: Coleman, Robert
Partner: UNT Libraries Government Documents Department

Interference of Tail Surfaces and Wing and Fuselage from Tests of 17 Combinations in the N.A.C.A. Variable-Density Tunnel

Description: An investigation of the interference associated with tail surfaces added to wing-fuselage combinations was included in the interference program in progress in the NACA variable-density tunnel. The results indicate that, in aerodynamically clean combinations, the increment of the high-speed drag can be estimated from section characteristics within useful limits of accuracy. The interference appears mainly as effects on the downwash angle and as losses in the tail effectiveness and varies with the geometry of the combination. An interference burble, which markedly increases the glide-path angle and the stability in pitch before the actual stall, may be considered a means of obtaining satisfactory stalling characteristics for complete combination.
Date: January 1, 1939
Creator: Sherman, Albert
Partner: UNT Libraries Government Documents Department

An instrument for estimating tautness of doped fabrics on aircraft

Description: Technical note presenting the design and use of a spring-loaded tautness meter that can be used in both horizontal and vertical positions to compare the tautness of various panels. Results of tests made on the fabric coverings of various airplanes are reported and discussed.
Date: September 1939
Creator: Kline, Gordon M. & Schiefer, Herbert F.
Partner: UNT Libraries Government Documents Department

Investigations and tests in the towing basin at Guidonia

Description: 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 1, 1939
Creator: Cremona, C
Partner: UNT Libraries Government Documents Department

Investigations and experiments in the Guidonia wind tunnel

Description: This paper is a presentation of the experiments and equipment used in investigations at the Guidonia wind tunnel. The equipment consisted of: a number of subsonic and supersonic cones, an aerodynamic balance, and optical instruments operating on the Schlieren and interferometer principle.
Date: July 1, 1939
Creator: Ferri, Antonio
Partner: UNT Libraries Government Documents Department

Measurements of the air-flow velocity in the cylinder of an airplane engine

Description: The object of the present investigation is to determine the velocity in the BMW-VI cylinder of an externally driven single-cylinder test engine at high engine speeds using the hot-wire method of Ulsamer.
Date: December 1, 1939
Creator: Wenger, Hermann
Partner: UNT Libraries Government Documents Department

Photoelastic analysis of three-dimensional stress systems using scattered light

Description: A method has been developed for making photoelastic analyses of three-dimensional stress systems by utilizing the polarization phenomena associated with the scattering of light. By this method, the maximum shear and the directions of the three principal stresses at any point within a model can be determined, and the two principal stresses at a free-bounding surface can be separately evaluated. Polarized light is projected into the model through a slit so that it illuminates a plane section. The light is continuously analyzed along its path by scattering and the state of stress in the illuminated section is obtained. By means of a series of such sections, the entire stress field may be explored. The method was used to analyze the stress system of a simple beam in bending. The results were found to be in good agreement with those expected from elementary theory.
Date: November 1, 1939
Creator: Weller, R & Bussey, J K
Partner: UNT Libraries Government Documents Department

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. In the pack test an odd number of specimens are assembled into a relatively stable pack, like a "pack of cards." Additional lateral stability is obtained from lateral supports between the external sheet faces of the pack and outside reactions. The tests seems adequate for many problems in structural research.
Date: January 1, 1939
Creator: Aitchison, C S & Tuckerman, L B
Partner: UNT Libraries Government Documents Department

Wind-tunnel investigation of ground effect on wings with flaps

Description: From Summary: "An investigation was conducted in the N.A.C.A. 7- by 10-foot wind tunnel to determine the effect of ground proximity on the aerodynamic characteristics of wings equipped with high-lift devices. A rectangular and a tapered wing were tested without flaps, with a split flap, and with a slotted flap. The ground was represented by a flat plate, completely spanning the tunnel and extending a considerable distance ahead and back of the model. The position of the plate was varied from one-half to three chord lengths below the wing. The results are presented in the form of curves of absolute coefficients, showing the effect of the ground on each wing arrangement."
Date: May 1939
Creator: Recant, Isidore G.
Partner: UNT Libraries Government Documents Department

Preliminary Report on Laminar-Flow Airfoils and New Methods Adopted for Airfoil and Boundary-Layer Investigations

Description: Recent developments in airfoil-testing methods and fundamental air-flow investigations, as applied to airfoils, are discussed. Preliminary test results, obtained under conditions relatively free from stream turbulence and other disturbances, are presented. Suitable airfoils and airfoil-design principles were developed to take advantage of the unusually extensive laminar boundary layers that may be maintained under the improved testing conditions. The results are of interest mainly in range of below 6,000,000.
Date: June 1, 1939
Creator: Jacobs, Eastman N.
Partner: UNT Libraries Government Documents Department

Pressure-distribution investigation of an N.A.C.A. 0009 airfoil with a 50-percent-chord plain flap and three tabs

Description: Pressure-distribution tests of an N.A.C.A. 0009 airfoil with a 50-percent-chord plain flap and three plain tabs, having chords 10, 20, and 30 percent of the flap chord, were made in the N.A.C.A. 4- by 6- foot vertical tunnel. The tests supplied aerodynamic section data that may be applied to the design of horizontal and vertical tail surfaces. The results are presented as resultant-pressure diagrams for the airfoil with the flap and the 20-percent-chord tab. Plots are also given of increments of normal-force and hinge-moment coefficients for the airfoil, the flap, and the three tabs. The experimental results and values computed by analytical methods are in good agreement for small flap and tab deflections. The results of the tests indicated that the effectiveness of all three tab sizes in reducing flap hinge moments decreased with increasing flap deflection.
Date: November 1, 1939
Creator: Street, William G & Ames, Milton B
Partner: UNT Libraries Government Documents Department

Local instability of symmetrical rectangular tubes under axial compression

Description: A chart is presented for the coefficient in the formula for the critical compressive stress at which cross sectional distortion begins in a thin-wall tube of rectangular section symmetrical about its two principal axes. The energy method of Timoshenko was used in the theoretical calculations required for the construction of the chart. The deflection equation used in this method was selected to give good accuracy. The exact values given by solution of the differential equation were calculated for a number of cases and it was found that the energy solution was correct to within a fraction of 1 percent. The calculation of the critical compressive stress at stresses above the elastic range is also discussed. In order to demonstrate the use of the formulas and the chart in engineering calculations, several illustrative problems are included.
Date: February 1, 1939
Creator: Lundquist, Eugene E.
Partner: UNT Libraries Government Documents Department

Loads imposed on intermediate frames of stiffened shells

Description: The loads imposed on intermediate frames by the curvature of the longitudinal and by the diagonal-tension effects are treated. A new empirical method is proposed for analyzing diagonal-tension effects. The basic formulas of the pure diagonal-tension theory are used, and the part of the total shear S carried by diagonal tension is assumed to be given the expression S (sub DT) = S (1-tau sub o/tau)(sup n) where tau (sub o) is the critical shear stress, tau the total (nominal shear stress), and n = 3 - sigma/tau where sigma is the stress in the intermediate frame. Numerical examples illustrate all cases treated.
Date: February 1, 1939
Creator: Kuhn, Paul
Partner: UNT Libraries Government Documents Department

Local instability of centrally loaded columns of channel section and Z-section

Description: Charts are presented for the coefficients in formulas for the critical compressive stress at which cross-sectional distortion begins in a thin-wall member with either a channel section or a Z-section with identical flanges. The energy method of Timoshenko was used in the theoretical calculations required for the construction of the charts. The deflection equations were carefully selected to give good accuracy. The calculation of the critical compressive stress at stresses beyond the elastic range is briefly discussed. In order to demonstrate the use of the formulas and the charts in engineering calculations, two illustrative problems are included.
Date: August 1, 1939
Creator: Lundquist, Eugene E.
Partner: UNT Libraries Government Documents Department

Measurement of the true dynamic and static pressures in flight

Description: In this report, two reliable methods are presented, with the aid of which the undisturbed flight dynamic pressure and the true static pressure may be determined without error. These problems were solved chiefly through practical flight tests.
Date: October 1, 1939
Creator: Kiel, Georg
Partner: UNT Libraries Government Documents Department

Flight tests of retractable ailerons on a highly tapered wing

Description: A flight investigation was conducted to determine the lateral-control characteristics of retractable ailerons installed on a highly tapered wing. The effectiveness of the ailerons in producing roll was measured at various air speeds with full-span plain flaps both neutral and deflected 45 degrees. The direction of the yawing moment created by the ailerons was also noted. The lateral control provided by the retractable ailerons used in this investigation was approximately the same as that obtained with the plain ailerons of equal span with which the airplane was previously equipped. The amount of control available was found to be somewhat inadequate, apparently because of the rather short span of the ailerons (0.327 of the wing span). It is likely that, with an aileron span of from 0.50 to 0.60 of the wing span, a satisfactory degree of control would be obtained. With the full-span flaps deflected 45 degrees, the rolling action of the ailerons was increased about 30 percent over that obtained with the flaps neutral at the same speed. The yawing moment produced by the ailerons was in the same sense as the rolling moment, i.e., right roll was accompanied by yaw. Lag in the response of the rolling action to control application was not large enough to be noticed by the pilots. No appreciable control force was apparent to the pilots, which was considered somewhat undesirable. Minor modifications in the design of the ailerons, however, would probably correct this fault.
Date: June 1, 1939
Creator: Wetmore, J. W.
Partner: UNT Libraries Government Documents Department