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"Arise Americans" : your country and your liberty are in grave danger -- protect them now by joining the-- United States Navy or the U.S. Naval Reserve.

Description: A sailor in a white uniform uses a wrench on a large weapon or equipment. A blue border with white stars surrounds the top and sides of the picture. The bottom half of the poster is red, with white and blue text.
Date: June 18, 1941
Creator: Barclay, McClelland.
Partner: UNT Libraries Government Documents Department

Fight, let's go! : join the Navy.

Description: A sailor in a Service Dress Blue uniform carries a large white sea bag on his shoulder. He appears to be boarding a ship. Planes fly in the sky above him, some in formation. A large ship can be seen in the background.
Date: 1941
Creator: Barclay, McClelland.
Partner: UNT Libraries Government Documents Department

Direct Air Blast Exposure Effects in Animals, Operation Upshot-Knothole, Project 4.2

Description: Project 4.2 was designed to study direct (primary) air blast injury, in animals, from an atomic weapon in the range of 20 to 50 psi under circumstances affording protection against missiles, thermal and ionizing radiation and to estimate the probable direct air blast hazard in man. The pressure levels at which atomic weapons direct air blast injuries occur will determine, to a large extent, the number of blast casualties likely to be encountered. It is probable that fatal overpressures are not reached until well within the range at which indirect (secondary) blast, thermal and ionizing radiation are practically certain to prove fatal. Only in special situations affording partial protection from other injuries are blast injuries likely to be of practical importance. Two animal species of widely different body weights (700 rats and 56 dogs) were exposed, together with air pressure recorders, in aluminum cylinders, covered by sandbags and dirt but open at both ends, at seven stations distributed within the intended overpressure range of 20 to 50 psi of Shot 10« About 200 rats were likewise exposed in Shot 9. Unfortunately, the destructive effect of the air blast of Shot 10 was much greater than anticipated. Many of the exposure cylinders were displaced and their contents destroyed. Only a partial recovery of the animals was possible due to the excessive radioactive contamination which greatly limited the time in the area. Most of the animals were dead upon recovery. Those living were in a state of severe shock. Autopsy findings showed remarkably few traumatic lesions and lung hemorrhages in spite of the rough treatment and high overpressure to which they were subjected. The rats recovered from Shot 9 were exposed to a recorded pressure of 18 to 2k psi. The autopsy findings showed moderate lung hemorrhage in most of the animals ...
Date: December 31, 1953
Creator: Draeger, R. H. & Lee, R. H.
Partner: UNT Libraries Government Documents Department

Take the wheel : --steer a course for future success while serving your country in the United States Navy or the U.S. Naval Reserve.

Description: The upper half of the poster shows a painting of a large U.S. battleship, with additional ships seen in the background. In the lower half of the poster, to the left of the poster caption, is a small image of a naval officer looking through a porthole with binoculars and a sailor in a white uniform steering the ship.
Date: 1941
Creator: Murphey, Matt.
Partner: UNT Libraries Government Documents Department

Pershing's crusaders.

Description: In the foreground is an image of General Pershing on horseback, leading his troops. Two soldiers behind him hold flags: a U.S. flag and a red flag with a gold emblem. Hovering in the background is a hazy image of medieval crusaders on white horses, carrying heart-shaped shields with cross images on them.
Date: 1918~
Creator: United States. Army. Signal Corps.
Partner: UNT Libraries Government Documents Department

Estimated Effect of Ring Cowl on the Climb and Ceiling of an Airplane

Description: From Summary: "Although the application of a ring cowl to an airplane with an air-cooled engine increases the maximum L/D and the high speed to an appreciable extent, the performance in climb and ceiling is not increased as much as one would expect without analyzing the conditions. When a ring cowl is installed on an airplane, the propeller is set at a higher pitch to allow the engine to turn its rated r.p.m. at the increased high speed. V/nD is increased and the propeller efficiency at high speed is increased slightly. The ratio of r.p.m. at climbing speed, V(sub c) , to the r.p.m. at maximum speed, V (sub m) is dependent upon the ratio of V(sub c) to V(sub m)."
Date: June 1931
Creator: Louden, F. A.
Partner: UNT Libraries Government Documents Department

Collection of wind-tunnel data on commonly used wing sections

Description: This report groups in a uniform manner the aerodynamic properties of commonly used wing sections as determined from tests in various wind tunnels. The data have been collected from reports of a number of laboratories. Where necessary, transformation has been made to the absolute system of coefficients and tunnel wall interference corrections have been applied. Tables and graphs present the data in the various forms useful to the engineer in the selection of a wing section.
Date: January 1930
Creator: Louden, F. A.
Partner: UNT Libraries Government Documents Department

Flight tests on U.S.S. Los Angeles. Part 2: stress and strength determination

Description: From Summary: "The tests described in this report furnished data on the actual aerodynamic forces, and the resulting stresses and bending moments in the hull of the U. S. S. "Los Angeles" during as severe still-air maneuvers as the airship would normally be subjected to, and in straight flight during as rough air as is likely to occur in service, short of squall or storm conditions. The maximum stresses were found to be within the limits provided for in accepted practice in airship design. Normal flight in rough air was shown to produce forces and stresses about twice as great as the most severe still-air maneuvers."
Date: January 1930
Creator: Burgess, C. P.
Partner: UNT Libraries Government Documents Department

Bending moments, envelope, and cable stresses in non-rigid airships

Description: This report describes the theory of calculating the principal stresses in the envelope of a nonrigid airship used by the Bureau of Aeronautics, United States Navy. The principal stresses are due to the gas pressure and the unequal distribution of weight and buoyancy, and the concentrated loads from the car suspension cables. The second part of the report deals with the variations of tensions in the car suspension cables of any type of airship, with special reference to the rigid type, due to the propeller thrust or the inclination of the airship longitudinally.
Date: January 1923
Creator: Burgess, C. P.
Partner: UNT Libraries Government Documents Department

The torsional strength of wings

Description: This report describes a simple method for calculating the position of the elastic axis of a wing structure having any number of spars. It is shown that strong drag bracing near the top and bottom of a wing greatly increases the torsional strength. An analytical procedure for finding the contribution of the drag bracing to the torsional strength and stiffness is described, based upon the principle of least work, and involving only one unknown quantity. A coefficient for comparing the torsional rigidity of different wings is derived in this report.
Date: December 1928
Creator: Burgess, C. P.
Partner: UNT Libraries Government Documents Department

Forces on airships in gusts

Description: In this report it is shown that determining the instantaneous angle of pitch, the acceleration of the gust is as important as its maximum velocity or yaw. Hitherto it has been assumed that the conditions encountered in gusts could be approximately represented by considering the airship to be at an instantaneous angle of yaw or pitch (according to whether the gust is horizontal or vertical), the instantaneous angle being tan to the (-1) power (v/v), where v is the component of the velocity of the gust at right angles to the longitudinal axis of the ship, and v is the speed of the ship. An expression is derived for this instantaneous angle in terms of the speed and certain aerodynamic characteristics of the airship, and of the maximum velocity and the acceleration of the gust, and the application of the expression to the determination of the forces on the ship is illustrated by numerical examples.
Date: 1924
Creator: Burgess, C. P.
Partner: UNT Libraries Government Documents Department

Flow and Force Equations for a Body Revolving in a Fluid

Description: A general method for finding the steady flow velocity relative to a body in plane curvilinear motion, whence the pressure is found by Bernoulli's energy principle is described. Integration of the pressure supplies basic formulas for the zonal forces and moments on the revolving body. The application of the steady flow method for calculating the velocity and pressure at all points of the flow inside and outside an ellipsoid and some of its limiting forms is presented and graphs those quantities for the latter forms.
Date: December 1979
Creator: Zahm, A. F.
Partner: UNT Libraries Government Documents Department