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Natural History of the Tres Marías Islands, Mexico (open access)

Natural History of the Tres Marías Islands, Mexico

Brief description of the Tres Marías Islands, Mexico, including mammals, birds, reptiles, crustacea, and plants found there.
Date: April 29, 1899
Creator: Nelson, E. W.; Stejneger, Leonhard; Rathbun, Mary J. & Rose, J. N.
System: The UNT Digital Library
To Establish Glacier National Park in Montana, Report (open access)

To Establish Glacier National Park in Montana, Report

This report contains a recommendation by the Committee on Public Lands to pass Senate bill 5648 which proposes the creation of Glacier National Park in Montana. It includes letters of the Secretary of Interior and the Secretary of Agriculture in relation to the proposed bill, in addition to a map of the proposed boundaries and photographs of scenic landmarks.
Date: April 29, 1908
Creator: United States. Congress. Senate. Committee on Public Lands
System: The UNT Digital Library
A Systematic Synopsis of the Muskrats (open access)

A Systematic Synopsis of the Muskrats

From introduction: "Systematic account of the genus Fiber through study of over 1,000 specimens, chiefly well-prepared skins, accompanied by skulls, together with many odd skulls and skeletons."
Date: April 29, 1911
Creator: Hollister, N.
System: The UNT Digital Library
[Supplement A - First Quarterly Conference, St. Paul's Church] (open access)

[Supplement A - First Quarterly Conference, St. Paul's Church]

A handwritten document addressed to the members of the First Quarterly Conference (presumably of St. Paul's Church), reporting greater than normal church attendance and with the spiritual condition of the church described as unusually good. The document also expresses a need for a deep awakening and a new sense of God in Christ, and lists the names of 45 people who have recently been added to the church.
Date: January 29, 1919
Creator: unknown
System: The Portal to Texas History
Comparison of hecter fuel with export aviation gasoline (open access)

Comparison of hecter fuel with export aviation gasoline

Among the fuels which will operate at compression ratios up to at least 8.0 without preignition or "pinking" is hecter fuel, whence a careful determination of its performance is of importance. For the test data presented in this report the hecter fuel used was a mixture of 30 per cent benzol and 70 per cent cyclohexane, having a low freezing point, and distilling from first drop to 90 per cent at nearly a constant temperature, about 20 degrees c. below the average distillation temperature ("mean volatility") of the x gasoline (export grade). The results of these experiments show that the power developed by hecter fuel is the same as that developed by export aviation gasoline at about 1,800 r.p.m. at all altitudes. At lower speeds differences in the power developed by the fuels become evident. Comparisons at ground level were omitted to avoid any possibility of damaging the engine by operating with open throttle on gasoline at so high a compression. The fuel consumption per unit power based on weight, not volume, averaged more than 10 per cent greater with hecter than with x gasoline. The thermal efficiency of the engine when using hecter is less than when using gasoline, …
Date: January 29, 1920
Creator: Dickinson, H. C.; Gage, V. R. & Sparrow, S. W.
System: The UNT Digital Library
National Bureau of Standards: Its Functions and Activities (open access)

National Bureau of Standards: Its Functions and Activities

A report on the functions of the National Bureau of Standards.
Date: October 29, 1925
Creator: unknown
System: The UNT Digital Library
Air force and moment for N-20 wing with certain cut-outs (open access)

Air force and moment for N-20 wing with certain cut-outs

From Introduction: "The airplane designer often finds it necessary, in meeting the requirements of visibility, to remove area or to otherwise locally distort the plan or section of an airplane wing. This report, prepared for the Bureau of Aeronautics January 15, 1925, contains the experimental results of tests on six 5 by 30 inch N-20 wing models, cut out or distorted in different ways, which were conducted in the 8 by 8 foot wind tunnel of the Navy Aerodynamical Laboratory in Washington in 1924. The measured and derived results are given without correction for vl/v for wall effect and for standard air density, p=0.00237 slug per cubic foot."
Date: November 29, 1926
Creator: Smith, R. H.
System: The UNT Digital Library
Preliminary flight tests of the N.A.C.A. Roots type aircraft engine supercharger (open access)

Preliminary flight tests of the N.A.C.A. Roots type aircraft engine supercharger

"An investigation of the suitability of the N.A.C.A. Roots type aircraft engine supercharger to flight-operating conditions, as determined the effects of the use of the supercharger upon engine operation and airplane performance, is described in this report. Attention was concentrated on the operation of the engine-supercharger unit and on the improvement of climbing ability; some information concerning high speeds at altitude was obtained. The supercharger was found to be satisfactory under flight-operating conditions. Although two failures occurred during the tests, the causes of both were minor and have been eliminated" (p. 207).
Date: December 29, 1926
Creator: Gardiner, Arthur W. & Reid, Elliott G.
System: The UNT Digital Library
An Investigation of the Use of Discharge Valves and an Intake Control for Improving the Performance of N.A.C.A. Roots Type Supercharger (open access)

An Investigation of the Use of Discharge Valves and an Intake Control for Improving the Performance of N.A.C.A. Roots Type Supercharger

"This report presents the results of an analytical investigation on the practicability of using mechanically operated discharge valves in conjunction with a manually operated intake control for improving the performance of N. A. C. A. Roots type superchargers. These valves, which may be either of the oscillating or rotating type, are placed in the discharge opening of the supercharger and are so shaped and synchronized with the supercharger impellers that they do not open until the air has been compressed to the delivery pressure. The intake control limits the quantity of air compressed to engine requirements by permitting the excess air to escape from the compression chamber before compression begins" (p. 479).
Date: June 29, 1928
Creator: Schey, Oscar W. & Wilson, Ernest E.
System: The UNT Digital Library
The effect of increased carburetor pressure on engine performance at several compression ratios (open access)

The effect of increased carburetor pressure on engine performance at several compression ratios

The object of this investigation was to determine the effect of increasing the carburetor pressures from 30 to 40 inches of mercury, at compression ratios from 3.5 to 7.5, on the power, on the maximum cylinder pressures, on the fuel consumption, and on the other performance characteristics of an engine. A roots-type aircraft-engine supercharger was used to maintain the desired carburetor pressure.
Date: May 29, 1931
Creator: Schey, Oscar W. & Rollin, Vern G.
System: The UNT Digital Library
Paris Aviation Salon, 1934 (open access)

Paris Aviation Salon, 1934

This document reviews the Air show held in Paris in 1934. It includes charts and pictures of the aircraft which were from all parts of Europe.
Date: November 29, 1934
Creator: unknown
System: The UNT Digital Library
Preliminary tests in the NACA free-spinning wind tunnel (open access)

Preliminary tests in the NACA free-spinning wind tunnel

Typical models and the testing technique used in the NACA free-spinning wind tunnel are described in detail. The results of tests on two models afford a comparison between the spinning characteristics of scale models in the tunnel and of the airplanes that they represent.
Date: October 29, 1935
Creator: Zimmerman, C. H.
System: The UNT Digital Library
Effect of body nose shape on the propulsive efficiency of a propeller (open access)

Effect of body nose shape on the propulsive efficiency of a propeller

Report presents the results of an investigation of the propulsive efficiency of three adjustable propellers of 10-foot diameter operated in front of four body nose shapes, varying from streamline nose that continued through the propeller plane in the form of a large spinner to a conventional open-nose radial-engine cowling. One propeller had airfoil sections close to the hub, the second had conventional round blade shanks, and the third differed from the second only in pitch distribution. The blade-angle settings ranged from 20 degrees to 55 degrees at the 0.75 radius.
Date: January 29, 1940
Creator: Stickle, George W.; Crigler, John L. & Naiman, Irven
System: The UNT Digital Library
Preliminary investigation of the flying qualities of airplanes (open access)

Preliminary investigation of the flying qualities of airplanes

"The National Advisory Committee for Aeronautics is undertaking an investigation of the flying qualities of airplanes. The work consists in the determination of the significant qualities susceptible of measurement, the development of the instruments required to make the measurements, and the accumulation of data on the flying qualities of existing airplanes, which data are to serve as a basis for quantitative specifications for the flying qualities of future designs" (p. 449).
Date: March 29, 1940
Creator: Soulé, H. A.
System: The UNT Digital Library
The Calculated Effect of Various Hydrodynamic and Aerodynamic Factors on the Take-Off of a Large Flying Boat (open access)

The Calculated Effect of Various Hydrodynamic and Aerodynamic Factors on the Take-Off of a Large Flying Boat

Report presents the results of an investigation made to determine the influence of various factors on the take-off performance of a hypothetical large flying boat by means of take-off calculations. The factors varied in the calculations were size of hull (load coefficient), wing setting, trim, deflection of flap, wing loading, aspect ratio, and parasite drag. The take-off times and distances were calculated to the stalling speeds and the performance above these speeds was separately studied to determine piloting technique for optimum take-off.
Date: April 29, 1940
Creator: Olson, R. E. & Allison, J. M.
System: The UNT Digital Library
Measurement of Density of Liquid UF6 (open access)

Measurement of Density of Liquid UF6

This report describes a method and apparatus used to determine the density of liquid sodium hexafluoride. The report includes a drawing of the density cell used in the experiment.
Date: March 29, 1942
Creator: Priest, Homer F.
System: The UNT Digital Library
Interaction of Be with Fission Neutrons (open access)

Interaction of Be with Fission Neutrons

To determine whether or not the (n,2n) reaction in Be would produce a net increase in fission neutrons in a power plant, the distribution of In resonance neutrons slowed down from fission energies in a graphite block was measured with and without a 2" of Be in front of a U3O8 slab undergoing fission. The thermal neutrons producing the fissions were obtained by slowing down neutrons from a cyclotron source. The observed distribution without Be was well represented by a Gaussian source range 36 cm. (corresponding to an initial fission energy of 3 MeV) and a similar sink of range 7.8 cm. The total In resonance intensity with Be was 5% less than without Be. On the assumption that the effect of the Be is entirely due to its different mean free path and moderating power, the In distribution with Be was calculated. Since the m.f.p. as a function of energy is not known for Be, two separate calculations were made using the highest (2.9 cm.) and the lowest (1.80 cm.) possible values for the effective Be m.f.p. Both calculated curves were found to be higher than the observed Be distribution, indicating that at least 10% of the fission neutrons …
Date: April 29, 1942
Creator: Borst, L.; Allison, S. K.; Wheeler, John Archibald, 1911-2008 & Weinberg, Alvin Martin, 1915-2006
System: The UNT Digital Library
Theory of High Frequency Rectification by Silicon Crystals (open access)

Theory of High Frequency Rectification by Silicon Crystals

The excellent performance of British ''red dot'' crystals is explained as due to the knife edge contact against a polished surface. High frequency rectification depends critically on the capacity of the rectifying boundary layer of the crystal. C. For high conversion efficiency, the product of this capacity and of the ''forward'' (bulk) resistance R{sub b} of the crystal must be small. For a knife edge, this product depends primarily on the breadth of the knife edge and very little upon its length. The contact can therefore have a rather large area which prevents burn-out. For a wavelength of 10 cm. the computations show that the breadth of the knife edge should be less than about 10{sup -3} cm. For a point contact the radius must be less than 1.5 x 10{sup -3} cm. and the resulting small area is conductive to burn-out. The effect of ''tapping'' is probably to reduce the area of contact.
Date: October 29, 1942
Creator: Bethe, H. A.
System: The UNT Digital Library
Summary of an investigation of vanadium and uranium occurrence in Huerfano Park district, Raton Basin area, Huerfano and Costilla counties, Colorado (open access)

Summary of an investigation of vanadium and uranium occurrence in Huerfano Park district, Raton Basin area, Huerfano and Costilla counties, Colorado

A report on the SOM-vanadium occurrences of the Huerfano Park District.
Date: September 29, 1943
Creator: Emerson, John F.
System: The UNT Digital Library
Annual Report of the Boy Scouts of America: 1943 (open access)

Annual Report of the Boy Scouts of America: 1943

Annual report submitted by the Boy Scouts of America to Congress describing highlights from 1943, activities, membership, cooperating agencies, organizational leadership, and other information about scouting programs.
Date: March 29, 1944
Creator: Boy Scouts of America
System: The Portal to Texas History
Stability of Split Hollow Cylinders (open access)

Stability of Split Hollow Cylinders

Abstract: "The behavior of radially split hollow cylinders upon heating is discussed."
Date: June 29, 1944
Creator: Karush, William & Monk, A. T.
System: The UNT Digital Library
Technical Report for the Months of April, May and June, 1944; Chemical Research - General (open access)

Technical Report for the Months of April, May and June, 1944; Chemical Research - General

Technical report. Quite pure anhydrous ThCl4 in small quantity (8-10 g charge) has been prepared by the action of a mixture of Cl2 and CCl4 vapor on ThO2 at 675 degrees to 725 degrees C.
Date: July 29, 1944
Creator: Kraus, Charles A. (Charles August), 1875-1967
System: The UNT Digital Library
Longitudinal characteristics and aileron effectiveness of a midwing airplane from high-speed wind tunnel tests (open access)

Longitudinal characteristics and aileron effectiveness of a midwing airplane from high-speed wind tunnel tests

Report presenting wind-tunnel tests of a 0.175-scale model of a midwing airplane in order to determine the high-speed longitudinal characteristics, to test devices for improving longitudinal control at high Mach numbers, and to determine the aileron effectiveness at high Mach numbers. Force and moment coefficients are computed from test data. Control forces, elevator angle, and aileron angle for several flight conditions are predicted.
Date: September 29, 1944
Creator: Hall, Charles F. & Mannes, Robert L.
System: The UNT Digital Library
On the flow of a compressible fluid by the hodograph method 2: fundamental set of particular flow solutions of the Chaplygin differential equation (open access)

On the flow of a compressible fluid by the hodograph method 2: fundamental set of particular flow solutions of the Chaplygin differential equation

From Summary: "The differential equation of Chaplygin's jet problem is utilized to give a systematic development of particular solutions of the hodograph flow equations, which extends the treatment of Chaplygin into the supersonic range and completes the set of particular solutions. The particular solutions serve to place on a reasonable basis the use of velocity correction formulas for the comparison of incompressible and compressible flows. It is shown that the geometric-mean type of velocity correction formula introduced in part I has significance as an over-all type of approximation in the subsonic range."
Date: September 29, 1944
Creator: Garrick, I. E. & Kaplan, Carl
System: The UNT Digital Library