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Drag Measurements on a Junkers Wing Section: Application of the Betz Method to the Results of Comparative Tests Made on a Model and on an Airplane in Flight

Description: The comparison of model tests in flight can be based on the result of such measurements. They are very important from the aerodynamical point of view, as they lead to useful conclusions regarding the behavior of the wing, its best shape and the conformity of theoretical and actual flow. Although there still remains a certain prejudice against such measurements, I have still attempted to make these comparative tests in order to inspire confidence in their reliability.
Date: September 1927
Creator: Weidinger, Hanns
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Kinetographic Determination of Airplane Flight Characteristics

Description: The author's first experiments with a glider on flight characteristics demonstrated that an accurate flight-path measurement would enable determination of the polar diagram from a gliding flight. Since then he has endeavored to obtain accurate flight measurements by means of kinetograph (motion-picture camera). Different methods of accomplishing this are presented.
Date: April 1927
Creator: Raethjen, P.
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Researches on ailerons and especially on the test loads to which they should be subjected

Description: Aileron calculations have hitherto given greatly differing results according to different authors. It seems to be the general opinion that it is only necessary to give the ailerons such dimensions that the airplane can maneuver well, that the stresses they must undergo are relatively small, and that they are strong enough if their framework is of the order of strength as the wings to which they are attached. This article will show that the problem is really quite complex and that it should rece… more
Date: February 1927
Creator: Sabatier, J.
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Determining the Velocity Distribution in the Boundary Layer of an Airfoil Fitted With a Rotary Cylinder

Description: In the closer investigation of the results obtained from a wing model with a rotary cylinder mounted in its leading edge (NACA TM's 307 and 354), the velocity distribution in the vicinity of the surface of the model was determined by a hot-wire anemometer. The results confirmed the belief that the rotary cylinder had considerable effect on the air flow, but demonstrated the fact that the direct influence of the cylinder is confined to a very thin layer in immediate proximity to the surface.
Date: May 1927
Creator: Van der Hegge Zijnen, B. G.
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Approximation method for determining the static stability of a monoplane glider

Description: The calculations in this paper afford an approximate solution of the static stability. A derivation of the formulas for moment coefficient of a wing, moment coefficient of elevator, and the total moment of the combined wing and elevator and the moment coefficient with reference to the center of gravity are provided.
Date: November 1927
Creator: Lippisch, A.
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Cooperative Measurements of Radio Fading in 1925

Description: Scientific paper issued by the Bureau of Standards over studies conducted on radio fading. As stated in the abstract, "the series of measurements on fading were devoted to studies of fading effects during the sunset period, effects during the solar eclipse of January 24, the fading variations throughout a 24-hour day, and the effects of high transmitting power on fading" (p. 419). This paper includes tables, maps, illustrations, and photographs.
Date: August 17, 1927
Creator: Dellinger, J. H.; Jolliffe, C. B. & Parkinson, T.
open access

Passage of Solid Particles Through Rotary Cylindrical Kilns

Description: Technical paper issued by the Bureau of Mines over studies conducted on rotary kilns. As stated in the introduction, "the object of this study was to determine the factors that influence the rate of progress of crushed materials through a kiln" (p. 1). This paper includes tables, illustrations, and photographs.
Date: 1927
Creator: Sullivan, John D.; Maier, Charles G. & Ralston, Oliver C.
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Development, Mining, and Handling of Ore in Folded and Faulted Areas, Red Iron Mines, Birmingham District, Alabama

Description: Technical paper issued by the Bureau of Mines over mining of red iron ores in Birmingham, Alabama. As stated in the introduction, "the present paper deals more specifically with the development and handling of ore as affected by folds and faults in the ore bed, and considers changes that may be desirable or necessary in future mining practices" (p. 2). This paper includes illustrations, and photographs.
Date: 1927
Creator: Crane, W. R.
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Subsidence Due to Coal Mining in Illinois

Description: Report issued by the Bureau of Mines over investigations on surface subsidence from coal mining in Illinois. The results of the investigations are presented and discussed. This report includes tables, illustrations, and photographs.
Date: 1927
Creator: Herbert, Charles Arthur & Rutledge, J. J.
open access

The Ferric Sulphate-Sulphuric Acid Process: With a Chapter on Producing Small Bubbles of Gas in Liquids by Submerged Orifices

Description: Report issued by the Bureau of Mines over studies conducted on the ferric sulphate-sulphuric acid process. As stated in the introduction, "the work reported here comprises merely a study of the chemistry of the process and the mechanical conditions that would have to be observed in practice" (p. 1). This report includes tables, and illustrations.
Date: 1927
Creator: Ralston, Oliver C. & Maier, Charles G.
open access

Measurement of the Moments of Inertia of Full Scale Airplanes

Description: "This paper contains a description of the method of measuring the moments of inertia of full scale airplanes as practiced by the National Advisory Committee for Aeronautics at the Langley Memorial Aeronautical Laboratory. The method, while not at all new, is published for the information and guidance of others who may desire to make similar measurements. The paper includes as an appendix the computations for the moments of inertia of 0-2 airplane" (p. 1).
Date: September 1927
Creator: Green, M. W.
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