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The Preparation of 2, 2, 4, 4-Tetramethylpentane

Description: Report presenting seven distinct operations in the preparation of 2,2,4,4-tetramethylpentane, including the preparation of di-isobutylene hydrochloride, preparation of dimethylzinc, reaction of dimethylzinc in dry benzene with di-isobutylene hydrochloride, preliminary distillation of the reaction products, treatment of the first distillate with sodium and alcohol, final distillation after appropriate washing of the products, and recovery of the iodine in the zinc residues of II as methyl iodide.
Date: May 1942
Creator: Drake, N. L.
Partner: UNT Libraries Government Documents Department

Progress Summary Number 1: Mechanical Properties of Flush-Riveted Joints Submitted by Five Airplane Manufacturers

Description: Summary presenting information on flush-riveted joints for aircraft construction, including the strength, occurrence of defects, and effect of the angle of rivet head. The current tests covers specimens from 15 manufacturers of which 5 series have been completed and are described in this report.
Date: February 1942
Creator: Brueggeman, William Charles
Partner: UNT Libraries Government Documents Department

Effect of Normal Pressure on the Critical Compressive Stress of Curved Sheet

Description: Results are presented of tests of two specimens tested to study the effect of normal pressure on the critical compressive stress for thin curved sheets. These specimens are designated by their respective rib spacings of 10 inches and 30 inches. The relationship between compressive stress and normal pressure at which buckles disappeared is independent of whether the buckles were made to disappear by increase of normal pressure or decrease of compressive stress. (author).
Date: August 25, 1942
Creator: Rafel, Norman
Partner: UNT Libraries Government Documents Department

Tests of a Stressed-Carrying Door in Shear

Description: Bulletin presenting testing of a monocoque box with a stress-carrying door made and tested in torsion. The results indicate that if a stress-carrying door and its frame are made sufficiently heavy, the torsional stiffness of the box with the door can be made greater than the torsional stiffness of the box without the cut-out" (p. 1).
Date: August 1942
Creator: Gottlieb, Robert
Partner: UNT Libraries Government Documents Department

Tests of a Stress-Carrying Door in Compression

Description: Bulletin presenting the results of bending tests on a monocoque box with the door on the compression side. The results indicate that the effectiveness of a stress-carrying door depends on the intended function of the door.
Date: September 1942
Creator: Gottlieb, Robert
Partner: UNT Libraries Government Documents Department

A Description of the Ju 88 Airplane Anti-Icing Equipment

Description: Bulletin presenting an examination of a part of the anti-icing equipment for a Ju 88 airplane, including exhaust-air heat exchangers, control valves, air duct system, and air-heated wing panels. Testing was performed on the components and indicated that the thermal ice-prevention equipment can maintain the outer-wing panel free from ice.
Date: September 1942
Creator: Rodert, Lewis A. & Jackson, Richard
Partner: UNT Libraries Government Documents Department

The Fatigue Strengths of Some Wrought Aluminum Alloys

Description: Report presenting an exploration of fatigue stresses of some wrought aluminum alloys, including charts that cover different ranges of stress and number of cycles.
Date: June 1942
Creator: Stickley, G. W.
Partner: UNT Libraries Government Documents Department

Effect of Countersunk Depth on the Tightness of Two Types of Machine-Countersunk Rivet

Description: Bulletin presenting an investigation conducted to determine the effect of countersunk depth on the tightness of two types of machine-countersunk flush rivet. The specimens tested in the study were simple lap joints made by two different riveting methods. The results indicated that roundheaded rivets inserted from the back of the joint with the countersunk heads formed int he driving of the rivets produce tighter joints over a large range of depths than ordinary flush rivets.
Date: October 1942
Creator: Gottlieb, Robert
Partner: UNT Libraries Government Documents Department

The belt method for measuring pressure distribution

Description: "The measurement of pressure distribution may be accomplished rapidly for any number of locations deemed necessary in model or full-scale investigations by use of the 'belt' method. Reasonable accuracy may be obtained by careful use of this method" (p. 1).
Date: February 1943
Creator: Corson, Blake W., Jr.
Partner: UNT Libraries Government Documents Department

The Knock-Limited Performance of Fuel Blends Containing Spiropentane, Methylenecyclobutane, Di-Tert-Butyl Ether, Methyl Tert-Butyl Ether, and Triptane

Description: Tests show that at inlet-air temperatures of 250 deg F and 100 deg F the knock-limited performance of the base fuel of blends, leaded with 4 ml TEL per gallon and containing 20 percent spiropentane, was reduced at fuel/air ratios below 0.085. The 20 percent methylenecyclobutane reduced the knock-limited power of the base fuel at fuel/air ratios below 0.112. Di-tert-butyl ether, methyl-tert-butyl ether, and triptane increased the knock-limited power of the base fuel at all fuel/air ratios and at both temperatures.
Date: May 1946
Creator: Meyer, Carl L.
Partner: UNT Libraries Government Documents Department

XC-35 gust research project: Preliminary analysis of the lateral distribution of gust velocity along the span of an airplane

Description: Report presenting measurements of the lateral distribution of effective gust velocity along the span of the XC-35 airplane in a variety of weather conditions. Six standard shapes were determined from the distributions: triangular, rectangular, first trapezoidal, second trapezoidal, unsymmetrical, and double triangular.
Date: March 1943
Creator: Moskovitz, A. I.
Partner: UNT Libraries Government Documents Department

End-zone water injection as a means of suppressing knock in a spark-ignition engine

Description: Report discusses the results of an investigation into the effectiveness of water injection into the combustion end zone of a spark-ignition engine cylinder for the suppression of knock. The injection angle was found to be very important for obtaining maximum results. The results of various angles and amounts of water were examined.
Date: September 1944
Creator: Brun, Rinaldo J.; Olsen, H. Lowell & Miller, Cearcy D.
Partner: UNT Libraries Government Documents Department

Use of Internal Coolant as a Means of Permitting Increase in Engine Take-Off Power

Description: Engine tests, together with estimates made at Langley Memorial Aeronautical Laboratory, indicate that a 25-percent increase in take-off power can be obtained with present-day aircraft engines without increasing either the knock limit of the fuel or the external cooling requirements of the engine. This increase in power with present fuels and present external cooling is made possible through the use of an internal coolant inducted through the inlet manifold. Estimates on aircraft indicate that this 25-percent increase in power will permit an approximate usable increase of 8.5 percent in the take-off load of existing military airplanes. This increase in load is equivalent to an increase in the weight of gasoline normally carried of between 30 and 65 percent.
Date: January 1944
Creator: Rothrock, Addison M.
Partner: UNT Libraries Government Documents Department

An analysis of the fatigue life of an airplane wing structure under overload conditions

Description: From Introduction: "Fatigue life expectancy in normal transport operations was investigated in reference 1 and was found to be of equal importance with single-gust life. The effect of overload operation of transport airplanes on the probability of encountering single critical gusts was investigated in reference 2 and the frequency of critical gusts was found to increase rapidly with overload. The effect of overload operation on fatigue strength, however, has not heretofore been evaluated, hence the investigations of references 1 and 2 are combined herein to permit such evaluation and to determine the relative importance of fatigue and single-gust failures under conditions of overload operation."
Date: February 1946
Creator: Putnam, Abbott A. & Reisert, Thomas D.
Partner: UNT Libraries Government Documents Department

Tables and Charts for the Evaluation of Profile Drag From Wake Surveys at High Subsonic Speeds

Description: Report presents tables and charts for the evaluation of profile drag from wake surveys at high supersonic speeds. Two methods of evaluation are presented: an exact method that can be used on a wake of any shape and a simple approximate method that can be used when the variation of total-pressure loss across the wave has a typical form.
Date: July 1945
Creator: Block, Myron J. & Katzoff, S.
Partner: UNT Libraries Government Documents Department

A Positive-Replica Technique for Examining Finished Metal Surfaces and Its Application to Aircraft Engine Cylinders

Description: Report discusses a method of replica creation and testing of the surface-finish variation of aircraft engine parts subject to wear. In this report, a positive replica is created, the surface is treated, the replica is tested to make sure the fidelity is high enough, and a series of ring-sticking tests are conducted on the replicas. A summary of the results of the testing is also included.
Date: September 1944
Creator: Clark, Thomas P.
Partner: UNT Libraries Government Documents Department

A Preignition Indicator for Aircraft Engines

Description: Report describes an electrical-relay circuit that uses cylinder thermocouples for indicating preignition or misfiring in an aircraft engine. The potential dangers of preignition and the importance of an easy-to-use, practical preignition indicator are provided. The operating principles of the indicator and a description of its functioning, calibration, and installation procedures are also included.
Date: February 1945
Creator: Dallas, Thomas & Harries, Myron L.
Partner: UNT Libraries Government Documents Department

Notes on the Skipping of Seaplanes

Description: Report discusses five tests related to seaplane skipping and attempts to prevent it by changing the depths of step to avoid large suction force on the afterbody generated by the flow behind a shallow step. Flying boats of various sizes and weights were tested during landing and several degrees of trim were tested for boats that had a particularly shallow step. Design suggestions for future flying boats are also included.
Date: September 1943
Creator: Parkinson, John B.
Partner: UNT Libraries Government Documents Department

Notes on Unusual V-G Records From Transport Airplanes

Description: Report discusses some unusual velocity-acceleration records on transport airplanes, which the report defines as "records of accelerations experienced in flight that resulted from causes other than atmospheric gusts" (from Summary). The analysis of the records, which is required for determining proper classification, is described, and the sorting of the records into gust- or maneuver-related is described. The report also discusses the importance of receiving this data from flight operators in addition to the routine information they provide.
Date: August 1944
Creator: Walker, Walter G.
Partner: UNT Libraries Government Documents Department

Preliminary Investigation of the Relation of the Compressive Strength of Sheet-Stiffener Panels to the Diameter of Rivet Used for Attaching Stiffeners to Sheet

Description: Report discusses the results of compressive testing of 24S-T aluminum-alloy sheet-stiffener panels with five ratios of stiffener thickness to sheet thickness. For each ratio, rivets of five different diameters were used to attach the stiffeners to the sheets. The compressive strengths were found to increase with an increase in the diameter of the rivets until the ratio of rivet diameter to over-all thickness reached a certain point.
Date: November 1944
Creator: Dow, Norris F. & Hickman, William A.
Partner: UNT Libraries Government Documents Department

A Preliminary Study of Machine-Countersunk Flush Rivets Subjected to a Combined Static and Alternating Shear Load

Description: Report discusses the results of an investigation to study the effect of the height of a rivet head on the number of cycles required to cause failure of a machine-countersunk flush-riveted joint under a combined static and alternating shear load. A tight joint and a loose joint were tested and the number of cycles to failure and location of fatigue failure were compared.
Date: December 1943
Creator: Crate, Harold
Partner: UNT Libraries Government Documents Department

Preliminary Tank Experiments With a Hydrofoil on a Planing-Tail Seaplane Hull

Description: Report describes exploratory testing to determine the feasibility of using a hydrofoil with a type of flying boat afterbody called a planing tail. Several hydrofoil locations were examined, including no hydrofoil, and the effects of resistance characteristics were charted. The researchers concluded that it is possible to add a single hydrofoil to that type of afterbody to provide additional hydrodynamic lift without introducing instability.
Date: March 1944
Creator: Wadlin, Kenneth L.
Partner: UNT Libraries Government Documents Department