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Shell structures are important components of airplanes, missiles, and space vehicles, but present capabilities for predicting the local and general instability of many such structures are inadequate. A large effort continues to be devoted to the stability analysis of shell structures, and considerable progress has been made. Results are slowly disseminated, however, and many engaged in research are not fully cognizant of the problems and practices of the vehicle designers who utilize research results. Therefore, an NASA SYMPOSIUM ON INSTABILITY OF SKELL STRUCTURES was organized by the Langley Research Center with sessions held there on October 24 and 25, 1962. Participants were limited to persons contributing papers and to certain officials of the U.S. Government. This symposium was planned to provide those persons concerned with shell instability at research laboratories, at educational institutions, and in the aerospace industry with a comprehensive view of the present state of the art, including the voids in present knowledge, important current problems, and the most fruitful directions for future theoretical and experimental research on the instability of all types of shell structures. Individuals actively engaged in research on shell stability or design were invited to contribute written papers for inclusion in a compilation to be distributed to the participants prior to the symposium. A few papers were selected by a steering committee for oral presentation at the symposium. Provision was made, also, for a discussion of all papers.

This document contains reproductions of technical papers presented at the NACA Conference on Helicopters held at the Langley Aeronautical Laboratory May 12 and 13, 1954. The primary purpose of this conference was to convey to the military services, their contractors, and others concerned with the design of helicopters the results of NACA research on helicopters and to provide those attending an opportunity to discuss the results. The papers in this document are in the same form in which they were presented at the conference in order to facilitate their prompt distribution. The original presentation and this record are considered as complementary to, rather than as substitutes for, the Committee's more complete and formal reports . A list of the conferees is included.

Window surface is laid flat on top of photosensitive paper. Opposite side of glass is covered by black cloth. Window edges are then illuminated by light flash through fiber optics. Exposed paper is processed and inspected. Paper shows scratches, bubbles, dust particles, and fingerprints on glass surface.

Formal NASA technical reports and papers published in technical journals, and presentations by MSFC personnel during FY 1974 are presented. Papers from MSFC contractors are also included.

Formal NASA technical reports, papers published in technical journals, and presentations by MSFC personnel in FY73 are presented. Papers of MSFC contractors are also included.

Standard print-out proofing paper, preprinted with an identifying code, serves as convenient densitometer. Exposure to light darkens the paper and gives a measure of the density of the resultant photographic image or the total amount of exposure sustained by the paper.

Device automatically bench tests paper tape punches and readers in a simulated operating environment following routine maintenance. The reader and punch operate back-to-back and the paper tape output feeds the reader. The tape leader is prepunched with an arbitrary pattern that is continuously reproduced during the check.

Electronic circuit is used in a paper chromatograph instrument that has excellent sensitivity and furnishes a printed record of each test. The circuit measures and records changes in conductivity in a strip of chromatographic paper as different solutions are placed on it.

Contact temperature produced during rolling with spin

The nine papers included in this volume were presented by NASA research staff members at the National Meeting on the Future of Manned Military Aircraft sponsored by the Institute of the Aeronautical Sciences and held in San Diego, Calif., from August 1 to August 3, 1960. Because, together, they provide a comprehensive summary of research by NASA in the areas covered, they have been compiled in this publication for the information of personnel concerned with the design and procurement of manned military aircraft.

This document is a compilation of papers presented at the Conference on the Progress of the X-15 project held at the Langley Aeronautical Laboratory on 25-26 October 1956. The conference was held by the Research Airplane Committee of the U. S. Air Force, the U. S. Navy, and the National Advisory Committee for Aeronautics to report on the technical status of this research airplane. The papers were presented by members of the staffs of North American Aviation, Inc., Reaction Motors, Inc., and NACA.

The three papers collected here are: 'The Effect of Nose Shape on the Drag of Bodies of Revolution at Zero Angle of Attack.', 'Base Pressure on Wings and Bodies with Turbulent Boundary Layers', and 'Flow over Inclined Bodies'. The subject of the first paper is the drag of the nose section of bodies of revolution at zero angle of attack. The main object of the second paper is to summarize the prinicpal results of the many wind tunnel and free flight measurements of base pressure on both bodies of revolution and blunt trailing edge airfoils.

Paper is impregnated with mixture of methylene blue and ethylenediaminetetraacetic acid. Methylene blue is photo-reduced to leuco-form. Paper is kept isolated from oxygen until ready for use. Paper can be reused by photo-reduction after oxygen exposure.

The application is described of the digital program Pitch Paper Pilot to a presimulation analysis of a large delta wing aircraft similar to the Concorde supersonic transport. Pilot acceptance (in terms of Cooper-Harper ratings), pilot model parameters, and pilot-vehicle performance were predicted by Paper Pilot and compared to actual inflight measures. Results are good and illustrate the value of using the Paper Pilot concept during the planning stages of simulation.

A mathematical model for predicting the pilot rating of an aircraft in a roll task is described. The model includes: (1) the lateral-directional aircraft equations of motion; (2) a stochastic gust model; (3) a pilot model with two free parameters; and (4) a pilot rating expression that is a function of rms roll angle and the pilot lead time constant. The pilot gain and lead time constant are selected to minimize the pilot rating expression. The pilot parameters are then adjusted to provide a 20% stability margin and the adjusted pilot parameters are used to compute a roll paper pilot rating of the aircraft/gust configuration. The roll paper pilot rating was computed for 25 aircraft/gust configurations. A range of actual ratings from 2 to 9 were encountered and the roll paper pilot ratings agree quite well with the actual ratings. In addition there is good correlation between predicted and measured rms roll angle.

Papers are reported from the Special Session on Earth-Satellite Propagation Above 10 GHz, presented at The 1972 Spring Meeting of the United States National Committee, International Union of Radio Science, April 1972, Washington, D. C. This session was devoted to propagation measurements associated with the Applications Technology Satellite (ATS-5), which provided the first operational earth-space links at frequencies above 15 GHz. A comprehensive summary is presented of the major results of the ATS-5 experiment measurements and related radiometric, radar and meteorological studies. The papers are organized around seven selected areas of interest, with the results of the various investigators combined into a single paper presented by a principal author for that area. A comprehensive report is provided on the results of the ATS-5 satellite to earth transmissions. A complete list of published reports and presentations related to the ATS-5 Millimeter Wave Experiment is included.

Papers of Reichert and Wong (1971) and Reichert (1972) are referred to as erroneous in stating that in their work with cytochrome c sequences they demonstrated that vertebrates have achieved a higher organized genetic message with a higher fidelity in the DNA-to-protein information processing channel. Arguments are given to contest that statement.

Paper honeycomb is used for the construction of conventional, propeller-type, windmill blades. Using fairly simple techniques and conventional power tools, it is possible to shape both simple foils and more complex foils with or without tapered plan forms and with or without varying profiles. A block of honeycomb, in its compressed form, is mounted on a wedge and run through a bandsaw with the table at an appropriate tilt angle. It is the combination of the wedge angle and the table angle that gives the tapered planform and profile shape. Next the honeycomb is expanded on the shaft and jigged to give the desired angles of attack. With the honeycomb fixed in position, the blade is covered with a fine weave fiberglass cloth. Any surface quality can then be achieved with filling and sanding.

Limitations in the acquisition of nonlinear aerodynamic coefficients from free-oscillation data by means of the Chapman-Kirk technique, SAM-D control test vehicle trajectory plannning and flight test analysis, and determination of aerodynamic drag from radar data are among the topics covered in papers concerned with atmospheric flight mechanics. Other areas covered include fixed and rotary-wing aircraft, ordnance and reentry vehicles, and analysis and measurement techniques. Individual items are announced in this issue.

Critique of paper on Apollo 11 ilmenite basalts petrology and lunar bodies origin and form

SSS - paper tape punch and verify program for CDC 3200 computer

Critique of paper on earth core-mantle chemical equilibrium, considering upper mantle element abundance, oxidation state and volatiles nature

Critique of paper on lithosphere thermal regime descending into mantle

Bibliography of BOMEX papers and publications

Dipeptides separation and identification by column and paper chromatography for elution times prediction and sequence studies

Nonflammable paper is made from fibers of chrysotile asbestos, beta-glass fibers, glass microfibers, and a little nonflammable organic binder. It does not propagate flame in an atmosphere of 16.5-psig oxygen, and it is resistant to rot and mold, making it acceptable as wrapping material and for stored documents.

Annotated bibliography of FY 1970 scientific and technical reports, articles, papers, and presentations sponsored by NASA

Abstracts of conference papers on preliminary results from BOMEX and methods and techniques used to collect data

Critical review of Meisel paper on solar X ray source identification using D layer ionization behavior during eclipse

Paper chromatography combination with dinitrophenyl amino acids mass spectrometry for analyzing purine and pyrimidine bases

Compilation of technical papers in guidance theory, optimization theory, numerical methods, and celestial mechanics

Recording instrument paper speed effect on pulse wave measurements precision, discussing multiple observer studies of left ventricular ejection time

Physical properties and low flammability of glass paper modified with asbestos, microfiber glass, or beta glass additions

Pyrimidine and purine bases analysis by time of flight mass spectrometry and paper chromatography

Critique of paper on water crystal existence on Venus, presenting arguments against existence of clouds of micron sized ice crystals

Inorganic nonflammable paper prepared from vermiculite plus asbestos and glass fibers

Critical review of paper by E. N. Parker on confinement of magnetic field by beam of ions, discussing geomagnetic field equilibrium confinement mechanism

Critique of paper by Justus on energy balance of turbulence in upper atmosphere

Papers presented at symposium on metal-air batteries

Paper chromatography and mass spectrometry for analyses of pyrimidine and purine bases

Bibliography of formal NASA technical reports, papers, and presentations

Takeup reel receives continuous paper tapes from data recording machines. The roller is recessed to have four longitudinal members about its periphery which can be extended or retracted to change the overall diameter of the assembly to allow easy removal of the tapes.

Papers presented at high vacuum simulation techniques conference

Critique of paper by Carter and Kennedy regarding origin of diamonds in Canyon Diablo and Novo Urei meteorite

Implementation of programs for conversion of paper tape information to IBM 7090/94 magnetic tape, punched cards, and printed page

This compilation includes papers presented at the NASA Conference on Aircraft Operating Problems held at the Langley Research Center on May 10 - 12, 1965. Contributions were made by representatives of the Ames Research Center, the Flight Research Center, end the Langley Research Center of NASA, as well as by representatives of the Federal Aviation Agency.

Technical papers from AIAA/NASA Third Manned Space Flight Meeting at Houston in November 1964

Alumina-silica ceramic-fiber paper for traps and baffles in ultrahigh vacuum systems

The papers presented herein were taken from two Russian publications on the International Geophysical Year. The first four articles (footnoted Certain Articles Regarding Meteorology") are from Nekotoryye Problemy Meteorologii; Sbornik Statey, II Razdel Programmy MGG (Meteorologiya), No. 1, Izdat. Akademii Nauk SSSR (Certain Problems Regarding Meteorology; Collection of Articles, Second Section of the IGY Program (Meteorology), No. 1. Published by the Academy of Sciences Press) Moscow, 1960. The last two articles (footnoted "International Geophysical Year") are from Mezhdunarodnoy Geofizicheskiy God; Sbornik Statey i Materialov, Izdat. Leningradskogo Universiteta (International Geophysical Year; Collection of Articles and Materials. Published by the Leningrad University Press) 1960.

Preparing figures for technical papers