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  • 1
    Publication Date: 2019-07-11
    Description: A l/4-scale dynamically similar model of the XFV-1 airplane has been flown in the Ames 40- by 80-foot wind tunnel, using the trailing flight-cable technique. This investigation was devoted to establishing the flight characteristics of the model in forward flight from hovering to wing stall, and in yawed flight (wing span alined with the relative wind) from hovering to the maximum speed at which controlled flight could be maintained. Landings, take-offs, and hovering characteristics in flights close to the ground were also investigated.. Since the remote control system for the model was rather complicated and provided artificial damping about the pitch, roll, and yaw axes, sufficient data from the control-system calibration tests are included in this report to specify the performance of the control system in relation to both the model flight tests and the design of an automatic control system for the full-scale airplane. The model in hovering flight appeared to be neutrally stable. The response of the model to the controls was very rapid, and it was always necessary to provide some amount of artificial damping to maintain control. The model could be landed with little difficulty by hovering approximately a foot above the floor and then cutting the power. Take-offs were more difficult to perform, primarily because the rate of change in power to the model motors was limited by the characteristics of the available power source. The model was,capable of controlled yawed flight at translational velocities up to and including 20 feet per second. The effectiveness of the controls decreased with increasing speed, however, and at 25 fps control in pitch, and probably roll, was lost completely. The model was flown in controlled forward flight from hovering up to 70 fps. During these flights the model appeared to be more difficult to control in yaw than it was in pitch or roll. The flights of the model were recorded by motion picture cameras. These motion pictures are available on loan from NACA Headquarters as a film supplement to this report.
    Keywords: Aerodynamics
    Type: NACA-RM-SA52J15
    Format: application/pdf
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  • 2
    Publication Date: 2019-07-12
    Description: Dynamic--response measurements for various conditions of displacement and rate signal input, sensitivity setting, and simulated hinge moment were made of the three control-surface servo systems of an NAES-equipped remote-controlled airplane while on the ground. The basic components of the servo systems are those of the General Electric Company type G-1 autopilot using electrical signal. sources, solenoid-operated valves, and hydraulic pistons. The test procedures and difficulties are discussed, Both frequency and transient-response data, are presented and comparisons are made. The constants describing the servo system, the undamped natural frequency, and the damping ratio, are determined by several methods. The response of the system with the addition of airframe rate signal is calculated. The transfer function of the elevator surface, linkage, and cable system is obtained. The agreement between various methods of measurement and calculation is considered very good. The data are complete enough and in such form that they may be used directly with the frequency-response data of an airplane to predict the stability of the autopilot-airplane combination.
    Keywords: Aerodynamics
    Type: NACA-RM-SA50J05
    Format: application/pdf
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  • 3
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 42 (1996), S. 1772-1788 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The vapor-liquid equilibrium (VLE) of aqueous-organic mixtures is important in understanding the physical chemistry behind the contamination and remediation of contaminated surface water, ground water and unsaturated soils. The state of the science is assessed, and available VLE and solubility data are reviewed comprehensively for several organic compounds. Benzene, toluene, o-, m-, p-xylene, ethylbenzene, chloroform, 1,1,1-trichloroethane (TCA), and trichloroethylene (TCE) were included in this study. Correlations are provided for estimation of VLE as a function of temperature. A new VLE apparatus was developed to extend experimental techniques found in the literature. Partitioning data for several aqueous-organic systems were measured. The collected data compared very favorably to data available in the literature. The new procedure is capable of providing high-quality data over a wide range of liquid concentrations and temperatures.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 20 (1989), S. 350-355 
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Die quantitative Beschreibung von Verschleißschäden, deren Schadensbeurteilung und -verfolgung, sowie, bei hinreichender Kenntnis des Schadensmechanismus, die Schadensfrüherkennung des Verschleißortes ist für Komponenten des Maschinen- und Anlagenbaus von erheblicher Bedeutung. Im folgenden soll ein ambulantes Verfahren zur Schadensdokumentation vorgestellt werden, das die quantitative Inspektion von hochbeanspruchten Bauteiloberflächen bis in den Mikrometerbereich hinein ermöglicht.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim [u.a.] : Wiley-Blackwell
    Materials and Corrosion/Werkstoffe und Korrosion 25 (1974), S. 822-827 
    ISSN: 0947-5117
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Influence of mechanical stresses on the destruction by flow cavitationThe destruction produced by the formation of cavitation bubbles are enhanced in the presence of mechanical stresses. One may conclude therefrom that such effects will be encountered in the presence of residual stresses, too, e.g. in the case of cast steel pieces or in the vicinity of weld seams. Consequently the cavitation resistance may be improved by a thermal treatment (provided of course the treatment does not give rise to the formation of a corrosion sensitive structure). The destructions produced by cavitation are losses characterized by a specific crystallographic orientation. Erosion effects which are connected with cavitation on the other hand are not effected by mechanical stresses.
    Notes: Die Zerstörungen, die durch die Bildung von Kavitationsblasen hervorgerufen werden, sind in Gegenwart von mechanischen Spannungen verstärkt. Daraus ist zu schließen, daß auch im Falle von Eigenspannungen derartige Effekte auftreten, z. B. in Stahlgußstücken oder in der Nähe von Schweißnähten. Es folgt daraus, daß die Kavitationsbeständigkeit durch eine Wärmebehandlung verbessert werden kann (natürlich unter der Voraussetzung, daß dabei kein korrosionsanfälliges Gefüge entsteht). Im Falle der durch die Kavitation hervorgerufenen Zerstörungen handelt es sich um Materialverluste mit bestimmter kristallografischer Orientierung; im Gegensatz dazu werden die mit der Kavitation verbundenen Erosionseffekte durch mechanische Spannungen nicht verstärkt.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim [u.a.] : Wiley-Blackwell
    Materials and Corrosion/Werkstoffe und Korrosion 31 (1980), S. 1-14 
    ISSN: 0947-5117
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Cavitation corrosion, damage phenomenology and mechanisms-comparisons between flow cavitation corrosion, cavitation by rotating perforated disc and vibration cavitationIn a joint test programme involving different cavitation test devices (vibrator, rotating disc, flow channel) the influence of imploding cavitation bubbles on aluminium was investigated.The behaviour of the material was described in terms of macroscopical (mass loss-testing time and similar curves) and microscopical (investigations by SEM) methods.Lots of similarities in the kinetic of destruction and in the appearance of the damaged material could be found.
    Notes: Im Rahmen eines Ringversuches wurde in verschiedenen Kavitationsversuchseinrichtungen (Schwinger, rotierende Scheibe, Strömungskanal) die Auswirkung der implodierenden Blasen auf das Material Aluminium untersucht.Das Materialverhalten wurde makroskopisch (Masseverlust - Laufdauer - sowie daraus abgeleitete Kurven) und mikroskopisch (rasterelektronenmikroskopische Aufnahmen) erfaßt.Zahlreiche Gemeinsamkeiten im Schädigungsablauf und Schädigungsbild konnten festgestellt werden.
    Additional Material: 20 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 83 (1971), S. 848-849 
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 0009-286X
    Keywords: air injection ; bubble column ; circulation ; lakes ; mixing ; reservoirs ; stratification ; two phase flow ; Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Vanillic acid, which is potentially available from lignin, was converted to dibasic acids by etherifying the phenolic hydroxyl group with alkylene dihalides. The dibasic acids were esterified with ethylene glycol and condensed to linear polyesters. The polyesters were converted to fibers by melt spinning. The fibers could be stretched, preferably in a warm water bath, to give fibers with good tenacity and increased crystallinity as shown by birefringence measurements. The polyester obtained from ethylenedivanillic acid melted at 210°C. but softened and shrank at 80°C.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Protocatechuic acid which is available from tree sources was converted to a hydroxymethyl-1,4-benzodioxan carboxylic acid by reaction with epichlorohydrin. This hydroxy acid was condensed by heating under vacuum to from a linear polyester which was converted to fibers by melt spinning. By applying stretch during spinning a fiber with a tenacity of 4.4 g. per denier, a melting point of 210°C. and a softening point of 145°C. was obtained. Removal of one of the isomers formed in the preparation materially raised the softening point and raised the melting point above the decomposition temperature.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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