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  • Other Sources  (2,340)
  • MACHINE ELEMENTS AND PROCESSES  (1,202)
  • COMPUTERS  (1,138)
  • 1970-1974  (2,340)
  • 1925-1929
Collection
  • Other Sources  (2,340)
Source
Keywords
Years
Year
  • 1
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    Noise control of pneumatic percussion drills (1974)
    In:  CASI
    Details
    Publication Date: 2006-01-11
    Description: Noise sources in pneumatic drills are studied bringing to light the fact that air exhaust is the most important source. The present state of the art of noise control is discussed for pneumatic percussion drills abroad, indicating the different solutions adopted in this respect. Drills produced in Rumania are described and the results of noise measurements are shown.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 177-181
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  • 2
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    Contributions to the study of the characteristics of bearing noise and vibrations (1974)
    In:  CASI
    Details
    Publication Date: 2006-01-11
    Description: Results of experimental research on the noise and vibrations of radial ball and roller bearings are reported. Analysis of the frequency spectra disclosed dependences among vibration and noise, load, rpm and cage material. Some peculiar aspects of the frequency spectrum are also mentioned.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 131-135
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  • 3
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    Aspects of reducing spur gear noise (1974)
    In:  CASI
    Details
    Publication Date: 2006-01-11
    Description: Noise sources in gears and ways of improving their silence by profile shape alterations and wheel surface smoothness are discussed. Practical results obtained, from the noise point of view are reported, for textile machinery.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 124-130
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  • 4
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    Contributions to the reduction of gear noise (1974)
    In:  CASI
    Details
    Publication Date: 2006-01-11
    Description: The influence of profile displacements on the acoustic pressure level of running gears is studied. The conclusion is reached that extra polar gears function well, reducing the acoustic pressure level by about 2-3 db which, at the level of the total noise of 80-90 db, can be easily felt. This result can be explained by the fact that in this gear the pitch point is situated outside of the gearing segment, so that a certain change in the direction of the friction force between the tooth flanks is eliminated.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 118-123
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  • 5
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    Load influence on gear noise (1974)
    In:  CASI
    Details
    Publication Date: 2006-01-11
    Description: An original mathematical model is proposed to derive equations for calculation of gear noise. These equations permit the acoustic pressure level to be determined as a function of load. Application of this method to three parallel gears is reported. The logical calculation scheme is given, as well as the results obtained.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 112-117
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  • 6
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    Preliminary study of gear noise characteristics (1974)
    In:  CASI
    Details
    Publication Date: 2006-01-11
    Description: Experimental results and conclusions are presented about the noise characteristics of gears as a function of their operating conditions. The interpretive possibilities offered by real time noise and vibration spectrum analysis are emphasized. The noise reducing effects of light weight insulation boxes are also discussed.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 104-111
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  • 7
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    Considerations on the acoustic energy radiated by toothed gears (1974)
    In:  CASI
    Details
    Publication Date: 2006-01-11
    Description: A mechano-acoustic model is reported for calculating acoustic energy radiated by a working gear. According to this model, a gear is an acoustic coublet formed of the two wheels. The wheel teeth generate cylindrical acoustic waves while the front surfaces of the teeth behave like vibrating pistons. Theoretical results are checked experimentally and good agreement is obtained with open gears. The experiments show that the air noise effect is negligible as compared with the structural noise transmitted to the gear box.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 98-103
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  • 8
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    Acoustic determination of cracks in welded joints (1974)
    In:  CASI
    Details
    Publication Date: 2006-01-11
    Description: The acoustic analysis method permits detection of any cracks that might take place and their manner of propagation. The study deals with the cracks produced in experiments to determine the welding technology for a welded gray cast iron workpiece by using piezoelectric transducers to determine vibration acceleration.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 93-97
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  • 9
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    US studies in the field of shaft drilling on the lunar surface (1974)
    In:  CASI
    Details
    Publication Date: 2006-01-11
    Description: American equipment for drilling in the lunar surface is discussed, with emphasis on rotary-percussive methodology and core-sample retrieval techniques.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: Current Concepts Regarding the Moon (NASA-TT-F-766); p 192-205
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  • 10
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    Induction brazing at the Kennedy Space Center (1974)
    In:  Other Sources
    Details
    Publication Date: 2011-08-16
    Description: A description of the joint design, materials, equipment, qualification testing, inspection methods, and applications involved in performing induction brazing on hyperbolic propellants tubing at Kennedy Space Center. Induction brazing is a form of brazing in which the energy is transmitted to the workpiece by electrical induction; the eddy currents generated in the metal produce heat by resistance losses. Since induction heating is fast and highly localized, undesirable heat effects are minimized and the resulting braze is of high quality.
    Keywords: MACHINE ELEMENTS AND PROCESSES
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  • 11
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    Impact testing on composite fan blades (1974)
    In:  Other Sources
    Details
    Publication Date: 2011-08-16
    Description: The results of impact tests on large, fiber composite fan blades for aircraft turbofan engine applications are discussed. Solid composite blades of two different sizes and designs were tested. Both graphite/epoxy and boron/epoxy were evaluated. In addition, a spar-shell blade design was tested that had a boron/epoxy shell bonded to a titanium spar. All blades were tested one at a time in a rotating arm rig to simulate engine operating conditions. Impacting media included small gravel, two inch diameter ice balls, gelatin and RTV foam-simulated birds, as well as starlings and pigeons. The results showed little difference in performance between the graphite and boron/epoxy blades. The results also indicate that composite blades may be able to tolerate ice ball and small bird impacts but need improvement to tolerate birds in the small duck and larger category.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: SAMPE Quarterly; 5; July 197
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  • 12
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    Sealing of large leaks in high-vacuum systems subject to mechanical and thermal stresses (1974)
    In:  Other Sources
    Details
    Publication Date: 2011-08-16
    Description: The use of silicone rubber adhesive (particularly, G.E. RTV-108) for sealing large leaks in high vacuum systems subject to mechanical and thermal stresses is shown to be more effective than that of epoxy cements. The sealant is applied externally to the leak while the system is partially evacuated so that it is drawn into the hole.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: Journal of Vacuum Science and Technology; 11; July-Aug
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  • 13
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    Aluminized alloy boosts turbine blade life (1974)
    In:  Other Sources
    Details
    Publication Date: 2011-08-16
    Description: Description of an aluminized alloy coating technique that involves first the application of a ductile, oxidation-resistant overlay, such as NiCrAl, which is then partially aluminized. The duplex protective system has performance advantages over conventional aluminide coatings in that it provides higher-temperature hot corrosion resistance over a longer service life.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: Metal Progress; 106; Aug. 197
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  • 14
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    Friction and friction-generated temperature at a polymer-metal interface (1974)
    In:  Other Sources
    Details
    Publication Date: 2011-08-16
    Description: Results of friction and thermal tests of molded polyimide and pyrrone polymers are presented. The coefficient of sliding friction up to surface velocities of 2 m/sec and the coefficient of thermal expansion from 300 to 500 K were measured. An apparatus was constructed to measure simultaneously the coefficient of sliding friction and the friction-generated temperature. Measurements were made at a nominal pressure-velocity product of 0.25 MN/msec and at temperatures between 300 and 500 K.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: Polymer Engineering and Science; 14; Apr. 197
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  • 15
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    Families of shift-register sequences with impulsive correlation properties (1974)
    In:  Other Sources
    Details
    Publication Date: 2011-08-16
    Description: A study of the linear feedback shift registers corresponding to a subset of nonprimitive irreducible polynomials over GF(2) has uncovered a class of sequences with interesting structures and cyclic correlation properties. These families of sequences are made up of interleaved identical sequences which are from primitive irreducible polynomials. Furthermore, they have correlation functions which are two or three valued, being constant at zero or a small value throughout most of their length with the exception of a small number of impulses. Each interval between such impulses on the correlograms uniquely corresponds to (and thus uniquely identifies) the member sequence or sequences producing it. It is shown that these families of sequences have direct application as error-correcting codes.
    Keywords: COMPUTERS
    Type: IEEE Transactions on Information Theory; IT-20; Mar. 197
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  • 16
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    Solid state and fusion resistance spot welding of TD-NiCr sheet (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Keywords: MACHINE ELEMENTS AND PROCESSES
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  • 17
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    Ultrasonic examination of welded joints of great thickness in mechanical equipment under pressure (1974)
    In:  Other Sources
    Details
    Publication Date: 2011-08-16
    Description: The requirements involved in choosing ultrasonic devices, the factors that affect testing, and recommended calibration methods are discussed. The ultrasonic testing method is the only method that up to now permits detection of defects in welded joints of great thickness. The results are conditioned by the performances of the devices employed as well as by the degree of instruction of the personnel.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: the 4th Natl. Conf. on Acoustics, Vol. 2, B (NASA-TT-F-15663); p 199-203
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  • 18
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    Influence of ultrasounds on electrolytic polishing (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: On the basis of study of the electrolytic polishing of metal pieces, the following conclusions can be drawn: (1) Utilization of ultrasonically irradiated electrolytes in the electrolytic polishing of copper and steel pieces leads to enhanced polishing quality. (2) Polishing time for the reference pieces was twice as long as for the test pieces. (3) The chemical attack exerted on the surface of the test pieces in order to get the structure of the respective metal lasted less than half as long and yielded superior qualitative results in the copper as well as in the OT 60-2 steel test pieces polished with ultrasonically irradiated electrolytes. (4) The utilization of higher polishing current densities can be explained by the fact that the cavitational effect that arises in the electrolyte owing to ultrasounds contributes to an increase in the solution's electrical conductivity and elimination of gases from the electrolyte.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: the 4th Natl. Conf. on Acoustics, Vol. 2, B (NASA-TT-F-15663); p 210-214
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  • 19
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    Monitoring the presence of foreign bodies in the equipment (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: The methods for monitoring the presence of foreign bodies in radio electronic equipment are discussed. Descriptions of the structural design under the operating principle of the device for detecting foreign bodies weighing to 0.0026 grams are given.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: Technol. for the Production of Space Equipment (NASA-TT-F-15766); p 100-102
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  • 20
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    Process for manufacturing slit collimators (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: Peculiarities are described of the manufacturing process and the control of elements of slit collimators, the structural design of the required equipment and the process or assembling the collimators.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: Technol. for the Production of Space Equipment (NASA-TT-F-15766); p 89-91
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  • 21
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    Method of applying a mirror reflecting layer to instrument parts (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: A method follows for applying a mirror reflecting layer to the surfaces of parts, instruments, apparatus, and so on. A brief analysis is presented of the existing methods of obtaining the mirror surface and the advantages of the new method of obtaining the mirror surface by polymer casting mold are indicated.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: Technol. for the Production of Space Equipment (NASA-TT-F-15766); p 84-88
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  • 22
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    Process of manufacturing small-module gears with internal coupling (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: The small module geared coupling of an undulatory transmission is considered. Versions of the manufacture of gears with internal coupling and the instruments and equipment used, are reported.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: Technol. for the Production of Space Equipment (NASA-TT-F-15766); p 77-79
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  • 23
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    Process of manufacturing grids from wire less than 0.025 MM in diameter by the galvanic growth method (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: The process of manufacturing grids, the peculiarities of the structural design, the fittings, the requirements on the tools and work area are discussed.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: Technol. for the Production of Space Equipment (NASA-TT-F-15766); p 80-83
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  • 24
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    Prospective areas in the production technology of scientific equipment for space research (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: The average labor of individual types of operations in the percentage ratio of the total labor consumption of manufacturing scientific instruments and apparatus for space research is presented. The prospective areas in the production technology of billet, machining, mechanical assembly, installation and assembly, adjustment and regulation and testing and control operations are noted. Basic recommendations are made with respect to further reduction of labor consumption and an increase in the productivity of labor when manufacturing scientific equipment for space research.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: Technol. for the Production of Space Equipment (NASA-TT-F-15766); p 69-76
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  • 25
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    Servosystem with an undulatory reducing gear (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: The development of a potentiometric servosystem is described that has a dc microservomotor, which is the built in drive of an undulatory reducing gear. The operation of the system and the structural design of the undulatory reducing gear are elaborated. Results are presented from analyzing some tests of various types of undulatory reducing gear generators.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: Technol. for the Production of Space Equipment (NASA-TT-F-15766); p 44-53
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  • 26
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    Effectiveness of solid lubricant coatings for friction in hard vacuum (10-9 tor) (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: A study was made of the efficiency of solid lubricating coatings, based on MoS2 with various binders, during friction and under highvacuum conditions. Mass spectrometry was used for an analysis of the composition of the gas evolved from the coatings in the friction process. It is shown that the vacuum level, loading, and sliding velocity influence coating effectiveness. In the friction process the solid lubricant coatings yield characteristic decay products associated with the chemical nature of the binders. The mechanism of coating breakdown during friction is associated with the binder breakdown mechanism.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: Space Studies in the Ukraine, No. 1 (NASA-TT-F-15535); p 99-112
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  • 27
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    Influence of low temperatures of friction and wear (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: A brief review of studies on low-temperature friction are briefly reviewed. A facility and technique for studying friction both in air and in vacuum at temperatures of +20 and -190 C is described. Results of a wear study of structural steels operating together with chromium steel are presented. It is shown that reduction of the test temperature in vacuum leads in certain cases to marked increase of the wear magnitude and friction coefficient. This is associated not only with the general change of the mechanical properties of the materials but also with the influence of temperature reduction on the hardening and structural formation taking place in the surface layers during friction.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: Space Studies in the Ukraine, No. 1 (NASA-TT-F-15535); p 65-75
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  • 28
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    Study of the possibility of using solar radiant energy for welding and brazing metals (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: The solar spectrum at the surface of the earth is analyzed. A facility for creating concentrated solar radiant energy flux is described, and data on its energetic capabilities are presented. The technology of solar welding by the fusion technique and joining by high-temperature brazing is examined. The use of concentrated solar radiant energy for welding and brazing metals and alloys is shown. The results of mechanical tests and microscopic and macroscopic studies are presented.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: Space Studies in the Ukraine, No. 1 (NASA-TT-F-15535); p 9-18
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  • 29
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    Asperity lubrication and cavitation in face seals (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: The basic aspect of parallel-surface lubrication that distinguishes it from other areas of lubrication technology is that classical lubrication theory does not predict the existence of a stable hydrodynamic film for steady-state, isothermal, incompressible flow between smooth, parallel surfaces. Hydrodynamic films between apparently parallel surfaces have been observed in practice and are often essential for the reliable performance of thrust bearings and seals. In order to account for this fortunate discrepancy between classical theory and experiment, load-support mechanisms relating to accidential features characteristic of seal performance, which relax one or more of the assumptions in the classical theory and permit the theoretical prediction of load support are proposed. Some of the features that have been analyzed are vibratory effects such as wobble and bounce, surface waviness, nonsymmetric rotation resulting from various types of misalignment, lubricant density change, non-Newtonian lubricant effects, and surface roughness.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: NBS The Role of Cavitation in Mech. Failures; p 77-87
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  • 30
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    On particle motion in an electric welding arc treated with sonic or ultrasonic oscillations (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: The criteria for the stability of the subharmonic, harmonic, or superharmonic oscillations determine the relation between acoustic field parameters and particle parameters. The derived formulas underlie the destruction of the fragile Widmanstatten structure in weldings and therefore the designing of the generators that must be used for this welding process.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: The 4th Natl. Conf. on Acoustics, Vol. 2, B (NASA-TT-F-15663); p 131-138
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  • 31
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    Cracking and reformation of saturated hydrocarbons by ultrasound in the presence of water (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: The exposure of saturated hydrocarbons to ultrasound (800 kHz, 6 W/sq cm) in the presence of water results in: (1) cleavage of the carbon chain, producing saturated and unsaturated hydrocarbons with a lower number of carbons than the initial hydrocarbon (cracking); and (2) recombination after cleavage, producing saturated and unsaturated hydrocarbons with a higher number of carbons than the initial hydrocarbon (reformation). The addition of argon facilitates these phenomena. The effects are attributed to a homolytic (radical) mechanism occurring within the cavitation bubbles under the effects of microsparks.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: The 4th Natl. Conf. on Acoustics, Vol. 2, B (NASA-TT-F-15663); p 139-147
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  • 32
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    Contributions to the use of macrosounds for boiler decrusting (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: The results of an investigation indicate the following: (1) The deposition of incrustations on the heating surfaces of steam boilers can be prevented by inserting between heating surface and water an insulating layer on which the boiler incrustation will be deposited. (2) The insulating layer reduces the coefficient of heat transmission by 2%. (3) The insulating layer can be removed by macrosounds with a frequency of about 20 kHz, after any interval of boiler operation.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: The 4th Natl. Conf. on Acoustics, Vol. 2, B (NASA-TT-F-15663); p 126-130
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  • 33
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    Contributions to study of the stability of the electric welding arc under the action of acoustic pressure (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: During the treatment of an electric welding arc with ultrasonic oscillations, an improvement was found in overall source-arc stability. Theoretical explanations are provided for this phenomenon and formulas of equivalence between the classical arc and the treated arc are derived, taking stability as their criterion. A knowledge of this phenomenon can be useful in extending the applications of ultrasounds to different forms of electric arcs.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: The 4th Natl. Conf. on Acoustics, Vol. 2, B (NASA-TT-F-15663); p 118-125
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  • 34
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    Acoustical levitation for space processing (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: It is pointed out that many space-manufacturing processes will require the manipulation of weightless molten material within a container in such a way that the material does not touch the container wall. A description is given of an acoustical method which can be used for the positioning and shaping of any molten material including nonconductors such as glasses. The new approach makes use of an acoustical standing wave which is excited within an enclosure or resonator.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: Astronautics and Aeronautics; 12; July-Aug
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  • 35
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    Auger analysis of films formed on metals in sliding contact with halogenated polymers (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: The use of Auger electron spectroscopy (AES) to search for transferred polymer must contend with the fact that there has been no published work on Auger analysis of polymers. Since this is a new area for AES, the Auger spectra of polymers and of halogenated polymers in particular is discussed. It is shown that the Auger spectra of halogenated polymers have certain characteristics that permit an assessment of whether a polymeric transfer film has been established by sliding contact. The discussion is general and the concepts should be useful in considering the Auger analysis of any polymer. The polymers chosen for this study are the halogenated polymers polytetrafluoroethylene (PTFE), polyvinyl chloride (PVC), and polychlorotrifluorethylene (PCTFE).
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: Journal of Applied Physics; 45; July 197
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  • 36
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    Research on wood bending in a macrosonic field (1974)
    In:  Other Sources
    Details
    Publication Date: 2011-08-16
    Description: Woodworking often requires the wood to be bent into different shapes. In view of the fact that macrosonic waves compress and expand the medium through which they are being propagated we assumed that wood subjected to the action of these waves during the bending process would have enhanced plasticity as a result of the loosening-up that takes place in it, as well as of the reduction in effort. To this effect, the bending of wood plasticized in a macrosonic field was studied. This bending took place under good conditions, and structural analyses conducted with the aid of an electron microscope proved initial premises to be corrent. Applied on an industrial scale, this procedure would contribute to improving the technology of wood bending as well as to eliminating factory spoilage.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: The 4th Natl. Conf. on Acoustics, Vol. 2, B (NASA-TT-F-15663); p 234-237
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  • 37
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    Some aspects of using ultrasounds to improve sulfurous mineral flotation technology (1974)
    In:  Other Sources
    Details
    Publication Date: 2011-08-16
    Description: The results are discussed which were obtained with a new method of desorption of collector reagents connected with improving the selectivity of the flotation of copper and lead concentrate through the action of ultrasounds. Analysis of the results obtained by treating copper and lead concentrate in an ultraacoustic field indicates an increase in the copper content of the copper concentrate, of the lead content in the lead concentrate and, at the same time, a reduction in the lead of the copper concentrate.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: The 4th Natl. Conf. on Acoustics Vol. 2, B (NASA-TT-F-15663); p 112-117
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  • 38
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    On the dynamic stability of the focus of deformation in the cold drawing of tubes on an ultrasonically activated plug (1974)
    In:  Other Sources
    Details
    Publication Date: 2011-08-16
    Description: In the case of macrosonic drawing, it was experimentally determined that tube eccentricity is less than in the case of tube drawing without macrosonics. On this basis, a theoretical analysis was carried out of the effect of macrosounds on tube eccentricity, an analysis that qualitatively confirms the experimental data.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: The 4th Natl. Conf. on Acoustics, Vol. 2, B (NASA-TT-15663); p 102-111
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  • 39
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    Some research concerning the cold drawing of tubes on an ultrasonically activated plug (1974)
    In:  Other Sources
    Details
    Publication Date: 2011-08-16
    Description: The results are discussed of studies of the influence of macrosounds on a metal's friction and deformation conditions at the focus of deformation, on the mechanical characteristics of cold-drawn tubes, and on the dynamic stability of the focus of deformation. In the course of these studies, experimental equipment was developed and perfected. Under the proposed conditions the cold drawing of tubes on an ultrasonically activated plug turned out to be viable and efficient.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: The 4th Natl. Conf. on Acoustics, Vol. 2, B (NASA-TT-F-15663); p 89-96
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  • 40
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    Powder pressing in a macrosonic field (1974)
    In:  Other Sources
    Details
    Publication Date: 2011-08-16
    Description: An investigation was conducted to extend the technology of powder product manufacturing to new forms and sizes, to improve their quality as well as pressing efficiency and to reduce waste. In the course of metal and nonmetal powder briquette pressing, macrosounds were associated with the external static pressing force, which led to an increase in the relative height, density and physicomechanical characteristics of the briquettes. This method permits the extension of the range of products that can be manufactured from powders and the improvement of their quality.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: The 4th Natl. Conf. on Acoustics, Vol. 2, B (NASA-TT-F-15663); p 77-83
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  • 41
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    Metalworking with ultrasonic energy (1974)
    In:  Other Sources
    Details
    Publication Date: 2011-08-16
    Description: The application of ultrasonic radiation for metal working of steel is discussed. It is stated that the productivity of the ultrasonic working is affected by the hardness of the material to be worked, the oscillation amplitude, the abrasive temperature, and the grain size. The factors that contribute to an increase in the dislocation speed are analyzed. Experimental data are provided to substantiate the theoretical parameters.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: The 4th Natl. Conf. on Acoustics Vol. 2, B (NASA-TT-F-15663); p 60-66
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  • 42
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    Contributions to the study of ultrasonic machining (1974)
    In:  Other Sources
    Details
    Publication Date: 2011-08-16
    Description: Problems in the industrial application of ultrasounds are discussed. Starting from the industrial characteristics of ultrasonic working, especially of hard and fragile materials that are difficult to work by means of conventional methods, the characteristics of the feed system, the circulation system of the abrasive suspension, and the ultra-acoustic unit of machines for ultrasonic working are described. Experiments on the behavior of different types of ultra-acoustic unit design and on the optimal operating conditions connected with the manner of execution, fixation, and excitation conditions are analyzed.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: The 4th Natl. Conf. on Acoustics Vol. 2, B (NASA-TT-F-15663); p 53-59
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  • 43
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    Effect of gravity on liquid phase sintering (1974)
    In:  Other Sources
    Details
    Publication Date: 2019-01-25
    Description: The unique conditions offered by the earth orbital environment in material processing involving both solid and liquid phases, such as liquid phase sintering, were studied. An experimental development program involving both test and theoretical work was initiated. Experimental work using material combinations selected such that maximum information about the effect of gravity can be derived has been conducted. Wetting of the solid phase by the liquid during sintering is an important phenomenon in liquid phase sintering, and gravity has influence on both capillary phenomenon and density segregation; hence, material combinations were selected such that these two effects can be suitably studies. The experimental work is meant to form the basis for similar comparative work done under low-g conditions. The part of the model dealing with the capillary phenomenon, as related to liquid phase sintering and the effect of gravity on it, suggest that gravity will have negligible effect on the Bond number and that the cohesive force is dependent on both the amount of liquid phase and the angle of contact.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: Proc. of the 3d Space Processing Symp. on Skylab Results, Vol. 2; p 963-1001
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  • 44
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    Acoustic field positioning for containerless processing (1974)
    In:  Other Sources
    Details
    Publication Date: 2019-01-25
    Description: The non-contact positioning of materials in a space processing chamber is accomplished using a new type of acoustic levitator. Liquid and solid materials are positioned using a single source of sound. Fine control of position may be obtained by motion of an acoustical reflector. Electrical power required is usually less than 100 watts. The system operates satisfactorily at high and low temperatures and is adaptable as an add-on feature to existing space experiments. Containerless melting and solidification can be performed and a freely suspended liquid can be shaped to the contour of the sound field. Experiments are described in which aluminum, glass and plastic materials are melted and solidified in the containerless state. The system has applications to containerless crystal growth, melting and related processes.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: NASA. Marshall Space Flight Center Proc. of the 3d Space Processing Symp. on Skylab Results, Vol. 2; p 647-677
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  • 45
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    Acoustical positioning chamber for space processing (1974)
    In:  Other Sources
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    Publication Date: 2019-01-25
    Description: By readily levitating, positioning, and manipulating materials placed in it, the acoustical resonator can serve a variety of space processing operations, such as drawing crystals, degassing, and stirring of melts, and casting.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: NASA. Marshall Space Flight Center Proc. of the 3d Space Processing Symp. on Skylab Results, Vol. 2; p 679-690
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  • 46
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    System design considerations for free-fall materials processing (1974)
    In:  Other Sources
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    Publication Date: 2019-01-25
    Description: The design constraints for orbiting materials processing systems are dominated by the limitations of the flight vehicle/crew and not by the processes themselves. Although weight, size and power consumption are all factors in the design of normal laboratory equipment, their importance is increased orders of magnitude when the equipment must be used in an orbital facility. As a result, equipment intended for space flight may have little resemblance to normal laboratory apparatus although the function to be performed may be identical. The same considerations influence the design of the experiment itself. The processing requirements must be carefully understood in terms of basic physical parameters rather than defined in terms of equipment operation. Preliminary experiments and analysis are much more vital to the design of a space experiment than they are on earth where iterative development is relatively easy. Examples of these various considerations are illustrated with examples from the M518 and MA-010 systems. While these are specific systems, the conclusions apply to the design of flight materials processing systems both present and future.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: NASA. Marshall Space Flight Center Proc. of the 3d Space Processing Symp. on Skylab Results, Vol. 2; p 595-601
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  • 47
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    Lunar observations verifier editor programmer's manual, revision 1 (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: The prime purpose of the programmer's manual is to aid the programmer in understanding the programming aspects of the program. A description of the input, the printout, the deck setup, and tape configuration may be obtained from the LOVE user's guide.
    Keywords: COMPUTERS
    Type: NASA-CR-134258 , TRW-11176-H415-RO-02 , REV-1 , TRW-74-FMT-938-REV-1
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  • 48
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    ASTEP user's guide and software documentation (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: The Algorithm Simulation Test and Evaluation Program (ASTEP) is a modular computer program developed for the purpose of testing and evaluating methods of processing remotely sensed multispectral scanner earth resources data. ASTEP is written in FORTRAND V on the UNIVAC 1110 under the EXEC 8 operating system and may be operated in either a batch or interactive mode. The program currently contains over one hundred subroutines consisting of data classification and display algorithms, statistical analysis algorithms, utility support routines, and feature selection capability. The current program can accept data in LARSC1, LARSC2, ERTS, and Universal formats, and can output processed image or data tapes in Universal format.
    Keywords: COMPUTERS
    Type: NASA-CR-134303 , TRW-25990-H028-RO-00 , TRW-NOTE-74-FMT-939
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  • 49
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    Study of genetic direct search algorithms for function optimization (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: The results are presented of a study to determine the performance of genetic direct search algorithms in solving function optimization problems arising in the optimal and adaptive control areas. The findings indicate that: (1) genetic algorithms can outperform standard algorithms in multimodal and/or noisy optimization situations, but suffer from lack of gradient exploitation facilities when gradient information can be utilized to guide the search. (2) For large populations, or low dimensional function spaces, mutation is a sufficient operator. However for small populations or high dimensional functions, crossover applied in about equal frequency with mutation is an optimum combination. (3) Complexity, in terms of storage space and running time, is significantly increased when population size is increased or the inversion operator, or the second level adaptation routine is added to the basic structure.
    Keywords: COMPUTERS
    Type: NASA-CR-138619
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  • 50
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    Computer-assisted instruction (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: The results are presented of a project of research and development on strategies for optimizing the instructional process, and dissemination of information about the applications of such research to the instructional medium of computer-assisted instruction. Accomplishments reported include construction of the author language INSTRUCT, construction of a practical CAI course in the area of computer science, and a number of investigations into the individualization of instruction, using the course as a vehicle.
    Keywords: COMPUTERS
    Type: NASA-CR-138667
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  • 51
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    Reliability model derivation of a fault-tolerant, dual, spare-switching, digital computer system (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: A computer based reliability projection aid, tailored specifically for application in the design of fault-tolerant computer systems, is described. Its more pronounced characteristics include the facility for modeling systems with two distinct operational modes, measuring the effect of both permanent and transient faults, and calculating conditional system coverage factors. The underlying conceptual principles, mathematical models, and computer program implementation are presented.
    Keywords: COMPUTERS
    Type: NASA-CR-132441 , ER74-4108
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  • 52
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    Performance of gas-lubricated cruciform-mounted tilting-pad journal bearings and a damped flexibly mounted spiral-groove thrust bearing (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: A test program was conducted to determine the performance characteristics of gas-lubricated cruciform-mounted tilting-pad journal bearings and a damped spiral-groove thrust bearing designed for the Brayton cycle rotating unit (BRU). Hydrostatic, hybrid (simultaneously hydrostatic and hydrodynamic), and hydrodynamic tests were conducted in argon gas at ambient pressure and temperature ranges representative of operation to the 10.5 kWe BRU power-generating level. Performance of the gas lubricated bearings is presented including hydrostatic gas flow rates, bearing clearances, bearing temperatures, and transient performance.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: NASA-TM-X-2999 , E-7675
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  • 53
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    Effect of surface topography on structural growth of thick sputtered films (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Primarily thick sputtered S-Monel, silver, and 304 stainless steel coatings were deposited on mica, glass, and metal substrates with various surface finishes to investigate the structural growth of the coating by scanning electron microscopy. Compositional changes within the coating were analyzed by X-ray dispersion microscopy. Defects in the surface finish act as preferential nucleation sites and form isolated and complex nodules and various surface overgrowths in the coating. These nodules do not disappear after full annealing. Further, they have undesirable effects on mechanial properties; cracks are initiated at the nodules when the coating is stressed by mechanical forces. These effects are illustrated by micrographs. Nodular growth within a coating can be minimized or eliminated by reducing the surface roughness.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: NASA-TN-D-7577 , E-7655
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  • 54
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    Effect of frictional heating on brake materials (1974)
    In:  Other Sources
    Details
    Publication Date: 2019-06-27
    Description: An exploratory study of the properties of aircraft brake materials was made to determine ways of improving friction and wear behavior while minimizing surface temperatures. It is found that frictional variation at high temperature involves material softening and metal transfer, formation of oxides, and surface melting. The choice of proper materials to combat these effects is discussed. Minimum surface temperatures are found to result from use of materials with large density-specific heat and density-specific heat-conductivity factors, use of a higher load-lower friction system, and maximization of the contact area. Some useful trade-off criteria for the size of brake disks against weight considerations are suggested. Additional information on material behavior and peak braking temperatures was gathered from an inspection of used brake pads and rotor disks.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: Wear; 30; Oct. 197
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  • 55
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    The reliability impact of mission abort strategies on redundant flight computer systems (1974)
    In:  Other Sources
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    Publication Date: 2019-06-27
    Description: This correspondence presents a reliability model for a redundant flight computer system with standby sparing, taking into account various mission abort strategies. A mission rule to initiate a mission abort after a predetermined number of detected computer failures and to return to earth with the remaining computers is shown to result in: (1) little improvement of crew safety unless computer error coverage is nearly perfect, and (2) significant degradation in mission success whenever coverage is high.
    Keywords: COMPUTERS
    Type: IEEE Transactions on Computers; C-23; July 197
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  • 56
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    Unpowered to powered failure rate ratio - A key reliability parameter (1974)
    In:  Other Sources
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    Publication Date: 2019-06-27
    Description: It is shown that the initial assumption of the ratio of unpowered to powered failure rates can have a strong influence on the design of a modular system intended for space missions. The analysis is performed for parallel systems and for triple modular redundant systems. Parallel systems are shown to be much more sensitive to the unpowered to powered failure rate ratio than the TMR/Spares systems, however, regardless of which standby redundancy technique is considered, the dependence of the system reliability on this ratio increases as the number of standby spares increases.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: IEEE Transactions on Reliability; R-23; Apr. 197
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    Efficient generation of statistically good pseudonoise by linearly interconnected shift registers (1974)
    In:  Other Sources
    Details
    Publication Date: 2019-06-27
    Description: A number of efficient new algorithms for generating digital pseudonoise are presented. The algorithms are efficient because a large number of new pseudorandom bits are generated at each iteration of a computer implementation or at each clock pulse of a hardware implementation. The maximal-length shift register sequences obtained have good randomness properties. Some of the properties of p-n sequences are reviewed and the results of an extensive statistical evaluation of the pseudonoise are presented.
    Keywords: COMPUTERS
    Type: IEEE Transactions on Computers; C-23; Feb. 197
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  • 58
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    ATS-F/GEOS-C satellite to satellite tracking data processing consideration (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: The satellite to satellite tracking data unique processing considerations are presented. The strategy to be employed in the application of data processing routines to the ATS-F/GEOS-C satellite to satellite tracking experiment is described. When these considerations are included, studies, analysis and simulations predict an orbital position uncertainty of less than 15 meters and a velocity uncertainty of less than 1.5 millimeters per second.
    Keywords: COMPUTERS
    Type: NASA-TM-X-70736 , X-932-74-146
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  • 59
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    A brief description of the Medical Information Computer System (MEDICS) (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: The Medical Information Computer System (MEDICS) is a time shared, disk oriented minicomputer system capable of meeting storage and retrieval needs for the space- or non-space-related applications of at least 16 simultaneous users. At the various commercially available low cost terminals, the simple command and control mechanism and the generalized communication activity of the system permit multiple form inputs, real-time updating, and instantaneous retrieval capability with a full range of options.
    Keywords: COMPUTERS
    Type: NASA-TM-X-58138 , JSC-09080
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  • 60
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    Experimental evaluation of stresses in spherically hollow balls (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: An analysis was undertaken to evaluate stresses within spherically hollow ball bearings proportioned for 40, 50, and 60% mass reductions. Strain gage rosettes were used to determine principal strains and stresses in the steel ball models statically loaded in various orientations. Dimensionless results are reported for the balls under flate plate contact loads. Similitude considerations permit these results to be applied to calculate stresses in hollow ball bearings proportioned to these mass reductions.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: NASA-CR-2445
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    Design and testing of a tandem row pump inducer (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: The design and testing of a tandem row pump inducer having a supercavitating first stage with a 0.60 hub ratio is presented. The second stage tested was a helical impeller with a 0.70 hub ratio. A cubic arc transition was utilized to accomplish the hub change. The first stage had two blades and the free-vortex design approach was empirically modified based on previous experience. The recommended second stage design having four blades and using cambered blade section is presented but the model was not built or tested. The more simple helix was built instead to reduce cost. Data taken included head generation, cavitation observations and unsteady head fluctuations over the 0-100Hz range.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: NASA-CR-120374 , TR-7117-1
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  • 62
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    Scene correction (precision techniques) of ERTS sensor data using digital image processing techniques (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Techniques have been developed, implemented, and evaluated to process ERTS Return Beam Vidicon (RBV) and Multispectral Scanner (MSS) sensor data using digital image processing techniques. The RBV radiometry has been corrected to remove shading effects, and the MSS geometry and radiometry have been corrected to remove internal and external radiometric and geometric errors. The results achieved show that geometric mapping accuracy of about one picture element RMS and two picture elements (maximum) can be achieved by the use of nine ground control points. Radiometric correction of MSS and RBV sensor data has been performed to eliminate striping and shading effects to about one count accuracy. Image processing times on general purpose computers of the IBM 370/145 to 168 class are in the range of 29 to 3.2 minutes per MSS scene (4 bands). Photographic images of the fully corrected and annotated scenes have been generated from the processed data and have demonstrated excellent quality and information extraction potential.
    Keywords: COMPUTERS
    Type: PAPER-I14 , NASA. Goddard Space Flight Center 3d ERTS-1 Symp., Vol. 1, Sect. B; p 1909-1928
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    Evaluation of digitally corrected ERTS images (1974)
    In:  CASI
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    Publication Date: 2019-06-27
    Description: The discussion is limited to processes by which a set of data samples collected on a geometrically distorted grid can be converted to samples on a different precisely specified grid. It is assumed that a mathematical expression for the desired transformation already exists. Concern will be the effects on image quality (specifically loss of resolution, photometric accuracy, and miscellaneous aberations) that result from various techniques used in accomplishing the resampling. The resampling techniques evaluated have included nearest neighbor, bilinear, cubic convolution, and various truncated versions of sinc (x). The conclusion is that cubic convolution yields substantially higher quality output data for scenes typically encountered and can, in some instances, substantially enhance one's ability to abstract information.
    Keywords: COMPUTERS
    Type: PAPER-I10 , NASA. Goddard Space Flight Center 3d ERTS-1 Symp., Vol. 1, Sect. B; p 1837-1843
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  • 64
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    ERTS image data compression technique evaluation (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: The background and results of an investigation concerning the use of multispectral data compression in the ERTS program are presented. An average compression of greater than 2:1 has been achieved under the constraint of zero distortion in the reconstructed image, and four MSS tapes can be compressed to fill less than one reel of magnetic tape. A preliminary study of the hardware implementation of this processor proves the feasability of compression at input bit rates of over 100Mbs.
    Keywords: COMPUTERS
    Type: PAPER-I9 , NASA. Goddard Space Flight Center 3d ERTS-1 Symp., Vol. 1, Sect. B; p 1823-1835
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    A technique for correcting ERTS data for solar and atmospheric effects (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: A technique is described by which ERTS investigators can obtain and utilize solar and atmospheric parameters to transform spacecraft radiance measurements to absolute target reflectance signatures. A radiant power measuring instrument (RPMI) and its use in determining atmospheric paramaters needed for ground truth are discussed. The procedures used and results achieved in processing ERTS CCTs to correct for atmospheric parameters to obtain imagery are reviewed. Examples are given which demonstrate the nature and magnitude of atmospheric effects on computer classification programs.
    Keywords: COMPUTERS
    Type: PAPER-I7 , NASA. Goddard Space Flight Center 3d ERTS-1 Symp., Vol. 1, Sect. B; p 1787-1804
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    The Penn State ORSER system for processing and analyzing ERTS data (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: The Office for Remote Sensing of Earth Resources (ORSER) of the Space Science and Engineering Laboratory (SSEL) at The Pennsylvania State University has developed an extensive operational system for processing and analyzing ERTS-1 and similar multispectral data. Specific results obtained by using this system include a study of land use, discrimination between types of forest resources and vegetation, detection of previously unknown geologic faults and correlation of these with known mineral deposits and ground water, mapping of mine spoils in the anthracite region of eastern Pennsylvania, mapping of strip mines and acid mine drainage in Central Pennsylvania, agricultural land use mapping, and detection of gypsy moth infestation.
    Keywords: COMPUTERS
    Type: PAPER-I8 , NASA. Goddard Space Flight Center 3d ERTS-1 Symp., Vol. 1, Sect. B; p 1805-1822
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    Affine transformations from aerial photos to computer compatible tapes (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: During the development of a project to estimate wheat production, it became necessary to pull data, corresponding to particular fields in a test site, off an ERTS computer compatible tape. Aerial photographs and topographic maps were on hand for the test site. A method was devised, using an affine transformation, to relate the aerial photographs or topographic maps to the tapes. One can thereby access data on the tape corresponding to regions covered by only a few pixels. The theory can be used for the registration of two tapes for the same area and for the geometric correction of images.
    Keywords: COMPUTERS
    Type: PAPER-I3 , NASA. Goddard Space Flight Center 3d ERTS-1 Symp., Vol. 1, Sect. B; p 1719-1724
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    ESIAC: A data products system for ERTS imagery (time-lapse viewing and measuring) (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: An Electronic Satellite Image Analysis Console (ESIAC) has been developed for visual analysis and objective measurement of earth resources imagery. The system is being employed to process imagery for use by USGS investigators in several different disciplines studying dynamic hydrologic conditions. The ESIAC provides facilities for storing registered image sequences in a magnetic video disc memory for subsequent recall, enhancement, and animated display in monochrome or color. The unique feature of the system is the capability to time-lapse the ERTS imagery and/or analytic displays of the imagery. Data products have included quantitative measurements of distances and areas, brightness profiles, and movie loops of selected themes. The applications of these data products are identified and include such diverse problem areas as measurement of snowfield extent, sediment plumes from estuary dicharge, playa inventory, phreatophyte and other vegetation changes. A comparative ranking of the electronic system in terms of accuracy, cost effectiveness and data output shows it to be a viable means of data analysis.
    Keywords: COMPUTERS
    Type: PAPER-I4 , NASA. Goddard Space Flight Center 3d ERTS-1 Symp., Vol. 1, Sect. B; p 1725-1741
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    Advanced processing and information extraction techniques applied to ERTS-1 MSS data (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Conventional automatic data processing and information extraction techniques fall short of providing the information required by the user in some applications. For those cases, advanced techniques are needed to permit the extraction of the necessary information. Advanced techniques are described and examples of their application to ERTS-1 MSS data are provided. The techniques are designed to help overcome problems in location, mensuration, and classification accuracies which result from geometric distortions of the ERTS MSS data, the relatively coarse resolution of the sensor, and variations in atmospheric state over the region to be surveyed. It is shown that each of these factors can seriously degrade one's ability to extract necessary information. Further, it is shown that advanced techniques can alleviate the effects of these factors.
    Keywords: COMPUTERS
    Type: PAPER-I5 , NASA. Goddard Space Flight Center 3d ERTS-1 Symp., Vol. 1, Sect. B; p 1743-1772
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    Computer-implemented land use classification with pattern recognition software and ERTS digital data (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Significant progress has been made in the classification of surface conditions (land uses) with computer-implemented techniques based on the use of ERTS digital data and pattern recognition software. The supervised technique presently used at the NASA Earth Resources Laboratory is based on maximum likelihood ratioing with a digital table look-up approach to classification. After classification, colors are assigned to the various surface conditions (land uses) classified, and the color-coded classification is film recorded on either positive or negative 9 1/2 in. film at the scale desired. Prints of the film strips are then mosaicked and photographed to produce a land use map in the format desired. Computer extraction of statistical information is performed to show the extent of each surface condition (land use) within any given land unit that can be identified in the image. Evaluations of the product indicate that classification accuracy is well within the limits for use by land resource managers and administrators. Classifications performed with digital data acquired during different seasons indicate that the combination of two or more classifications offer even better accuracy.
    Keywords: COMPUTERS
    Type: PAPER-L1 , 3d ERTS-1 Symp., Vol. 1, Sect. A; p 331-337
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    An evaluation of machine processing techniques of ERTS-1 data for user applications (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: A broad study is described to evaluate a set of machine analysis and processing techniques applied to ERTS-1 data. Based on the analysis results in urban land use analysis and soil association mapping together with previously reported results in general earth surface feature identification and crop species classification, a profile of general applicability of this procedure is beginning to emerge. Put in the hands of a user who knows well the information needed from the data and also is familiar with the region to be analyzed it appears that significantly useful information can be generated by these methods. When supported by preprocessing techniques such as the geometric correction and temporal registration capabilities, final products readily useable by user agencies appear possible. In parallel with application, through further research, there is much potential for further development of these techniques both with regard to providing higher performance and in new situations not yet studied.
    Keywords: COMPUTERS
    Type: PAPER-A3 , NASA. Goddard Space Flight Center 3d ERTS-1 Symp., Vol. 1, Sect. A; p 41-73
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  • 72
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    Basic memory module (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Construction and electrical characterization of the 4096 x 2-bit Basic Memory Module (BMM) are reported for the Space Ultrareliable Modular Computer (SUMC) program. The module uses four 2K x 1-bit N-channel FET, random access memory chips, called array chips, and two sense amplifier chips, mounted and interconnected on a ceramic substrate. Four 5% tolerance power supplies are required. At the Module, the address, chip select, and array select lines require a 0-8.5 V MOS signal level. The data output, read-strobe, and write-enable lines operate at TTl levels. Although the module is organized as 4096 x 2 bits, it can be used in a 8196 x 1-bit application with appropriate external connections. A 4096 x 1-bit organization can be obtained by depopulating chips.
    Keywords: COMPUTERS
    Type: NASA-CR-120392 , IBM-74W-585-006
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  • 73
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    Convergence properties of simple genetic algorithms (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: The essential parameters determining the behaviour of genetic algorithms were investigated. Computer runs were made while systematically varying the parameter values. Results based on the progress curves obtained from these runs are presented along with results based on the variability of the population as the run progresses.
    Keywords: COMPUTERS
    Type: NASA-CR-139560 , TR-159
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  • 74
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    A fast-initializing digital equalizer with on-line tracking for data communications (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: A theory is developed for a digital equalizer for use in reducing intersymbol interference (ISI) on high speed data communications channels. The equalizer is initialized with a single isolated transmitter pulse, provided the signal-to-noise ratio (SNR) is not unusually low, then switches to a decision directed, on-line mode of operation that allows tracking of channel variations. Conditions for optimal tap-gain settings are obtained first for a transversal equalizer structure by using a mean squared error (MSE) criterion, a first order gradient algorithm to determine the adjustable equalizer tap-gains, and a sequence of isolated initializing pulses. Since the rate of tap-gain convergence depends on the eigenvalues of a channel output correlation matrix, convergence can be improved by making a linear transformation on to obtain a new correlation matrix.
    Keywords: COMPUTERS
    Type: NASA-CR-120312 , TR-166-102
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  • 75
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    GSE, data management system programmers/User' manual (1974)
    In:  CASI
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    Publication Date: 2019-06-27
    Description: The GSE data management system is a computerized program which provides for a central storage source for key data associated with the mechanical ground support equipment (MGSE). Eight major sort modes can be requested by the user. Attributes that are printed automatically with each sort include the GSE end item number, description, class code, functional code, fluid media, use location, design responsibility, weight, cost, quantity, dimensions, and applicable documents. Multiple subsorts are available for the class code, functional code, fluid media, use location, design responsibility, and applicable document categories. These sorts and how to use them are described. The program and GSE data bank may be easily updated and expanded.
    Keywords: COMPUTERS
    Type: NASA-TM-X-64862
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  • 76
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    Deployable flexible ventral fins for use as an emergency spin recovery device in aircraft (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: A flexible fin device for mounting on an aircraft to effect spin recovery is described. The device may be selectively deployed to provide a triangular planform of flexible material to provide spin recovery, and retracted for compact storage during non-use. A single flexible fin may be deflected in a specific direction depending on direction of spin rotation, or two flexible fins forming an inverted V configuration may be used. The device is mounted on the underbody of the aircraft.
    Keywords: COMPUTERS
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  • 77
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    Analysis of an all-metallic resilient-pad gas-lubricated thrust bearing (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: A resilient-pad gas thrust bearing that does not contain any elastomers in the bearing assembly is described and analyzed. The bearing consists of sector-shaped pads mounted asymmetrically on resilient foil beams. The effects of bearing design parameters on performance are shown. Performance of a resilient-pad bearing is compared with that of a pivoted-pad bearing.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: NASA-TN-D-7724 , E-7966
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  • 78
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    Comparison of experimental and predicted performance of 150-millimeter-bore solid and drilled ball bearings to 3 million DN (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Seven 150-millimeter-bore ball bearings were run under 8900-newton (2000-lbf) thrust load at speeds from 6670 to 20,000 rpm (1 million to 3 million DN). Four of the bearings had conventional solid balls, and three bearings had drilled (cylindrically hollow) balls with 50-percent mass reduction. The bearings were under-race cooled and slot lubricated with a type 2 ester oil at flow rates from 4.35 x 0.001 to 5.94 x 0.001 cubic meter/min (1.15 to 1.57 gal/min). Friction torque and temperature were measured on all bearings. While there was considerable spread in the temperature data, the drilled ball bearings tended to run slightly cooler than the solid ball bearings at higher speeds. No significant difference in torque was noted, however, between the solid and drilled ball bearings. One bearing of each type was rerun at 17,800-newton (4000-lbf) thrust load. The solid ball bearings performed satisfactorily at 3 million DN. However, at about 2 million DN the drilled ball bearing experienced a broken ball, and cracks appeared in other balls as a result of flexure fatigue. Metallurgical examination of the cracked balls indicated a brittle structure in the bore of the drilled balls.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: NASA-TN-D-7737 , E-7722
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  • 79
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    Combined effects of hydrazine exposure and endurance testing on solenoid-actuated valve performance (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Results are presented from a test program which was conducted to assess the capability of various solenoid-actuated valve design concepts to provide performance characteristics commensurate with long-duration (ten-year) missions to explore the outer planets. The valves were installed in a hydrazine flow test setup and periodically cycled during a nine-month test period under test conditions comparable to anticipated mission operating conditions. In situ valve performance was periodically determined, and leakage was continuously monitored.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: NASA-CR-139360 , JPL-TM-33-691
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  • 80
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    Global parallel unification for large question-answering systems (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: An efficient means of storing data in a first-order predicate calculus theorem-proving system is described. The data structure is oriented for large scale question-answering (QA) systems. An algorithm is outlined which uses the data structure to unify a given literal in parallel against all literals in all clauses in the data base. The data structure permits a compact representation of data within a QA system. Some suggestions are made for heuristics which can be used to speed-up the unification algorithm in systems.
    Keywords: COMPUTERS
    Type: NASA-CR-139212 , TR-307
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  • 81
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    Computer programs for calculation of matrix stability and frequency response from a state-space system description (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: FORTRAN computer subroutines stemming from requirements to process state variable system equations for systems of high order are presented. They find the characteristic equation of a matrix using the method of Danilevsky, the number of roots with positive real parts using the Routh-Horwitz alternate formulation, convert a state variable system description to a Laplace transfer function using the method of Bollinger, and evaluate that transfer function and obtain its frequency response. A sample problem is presented to demonstrate use of the subroutines.
    Keywords: COMPUTERS
    Type: NASA-TM-X-71581 , E-8016
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    A real-time digital computer program for the simulation of a single rotor helicopter (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: A computer program was developed for the study of a single-rotor helicopter on the Langley Research Center real-time digital simulation system. Descriptions of helicopter equations and data, program subroutines (including flow charts and listings), real-time simulation system routines, and program operation are included. Program usage is illustrated by standard check cases and a representative flight case.
    Keywords: COMPUTERS
    Type: NASA-TM-X-2872 , L-9002
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  • 83
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    Houston Operations Predictor/Estimator (HOPE) programming manual, volume 1 (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: The programming techniques used to implement the equations and mathematical techniques of the Houston Operations Predictor/Estimator (HOPE) orbit determination program on the UNIVAC 1108 computer are described. Detailed descriptions are given of the program structure, the internal program structure, the internal program tables and program COMMON, modification and maintainence techniques, and individual subroutine documentation.
    Keywords: COMPUTERS
    Type: NASA-CR-134368 , TRW-25990-H004-RO-00-VOL-1 , TRW-74-FMT-932-VOL-1
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    HAL/S-FC compiler system functional specification (1974)
    In:  CASI
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    Publication Date: 2019-06-27
    Description: Compiler organization is discussed, including overall compiler structure, internal data transfer, compiler development, and code optimization. The user, system, and SDL interfaces are described, along with compiler system requirements. Run-time software support package and restrictions and dependencies are also considered of the HAL/S-FC system.
    Keywords: COMPUTERS
    Type: NASA-CR-134372 , IR-59-4
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  • 85
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    Users guide for information retrieval using APL (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: A Programming Language (APL) is a precise, concise, and powerful computer programming language. Several features make APL useful to managers and other potential computer users. APL is interactive; therefore, the user can communicate with his program or data base in near real-time. This, coupled with the fact that APL has excellent debugging features, reduces program checkout time to minutes or hours rather than days or months. Of particular importance is the fact that APL can be utilized as a management science tool using such techniques as operations research, statistical analysis, and forecasting. The gap between the scientist and the manager could be narrowed by showing how APL can be used to do what the scientists and the manager each need to do, retrieve information. Sometimes, the information needs to be retrieved rapidly. In this case APL is ideally suited for this challenge.
    Keywords: COMPUTERS
    Type: NASA-TM-X-69914 , NSSDC-74-11
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  • 86
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    HAL/S programmer's guide (1974)
    In:  CASI
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    Publication Date: 2019-06-27
    Description: This programming language was developed for the flight software of the NASA space shuttle program. HAL/S is intended to satisfy virtually all of the flight software requirements of the space shuttle. To achieve this, HAL/s incorporates a wide range of features, including applications-oriented data types and organizations, real time control mechanisms, and constructs for systems programming tasks. As the name indicates, HAL/S is a dialect of the original HAL language previously developed. Changes have been incorporated to simplify syntax, curb excessive generality, or facilitate flight code emission.
    Keywords: COMPUTERS
    Type: NASA-CR-134371 , IR-63-3
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  • 87
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    On-line diagnosis of sequential systems, 2 (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: The theory and techniques applicable to the on-line diagnosis of sequential systems, were investigated. A complete model for the study of on-line diagnosis is developed. First an appropriate class of system models is formulated which can serve as a basis for a theoretical study of on-line diagnosis. Then notions of realization, fault, fault-tolerance and diagnosability are formalized which have meaningful interpretations in the the context of on-line diagnosis. The diagnosis of systems which are structurally decomposed and are represented as a network of smaller systems is studied. The fault set considered is the set of faults which only affect one component system is the network. A characterization of those networks which can be diagnosed using a purely combinational detector is achieved. A technique is given which can be used to realize any network by a network which is diagnosable in the above sense. Limits are found on the amount of redundancy involved in any such technique.
    Keywords: COMPUTERS
    Type: NASA-CR-139372 , UMICH-012146-1-T , SEL-TR-81
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  • 88
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    On the recognition of complex structures: Computer software using artificial intelligence applied to pattern recognition (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: An approach to simultaneous interpretation of objects in complex structures so as to maximize a combined utility function is presented. Results of the application of a computer software system to assign meaning to regions in a segmented image based on the principles described in this paper and on a special interactive sequential classification learning system, which is referenced, are demonstrated.
    Keywords: COMPUTERS
    Type: NASA-CR-139363 , JPL-TM-33-693
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  • 89
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    Design of FIR digital filters for pulse shaping and channel equalization using time-domain optimization (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Three algorithms are developed for designing finite impulse response digital filters to be used for pulse shaping and channel equalization. The first is the Minimax algorithm which uses linear programming to design a frequency-sampling filter with a pulse shape that approximates the specification in a minimax sense. Design examples are included which accurately approximate a specified impulse response with a maximum error of 0.03 using only six resonators. The second algorithm is an extension of the Minimax algorithm to design preset equalizers for channels with known impulse responses. Both transversal and frequency-sampling equalizer structures are designed to produce a minimax approximation of a specified channel output waveform. Examples of these designs are compared as to the accuracy of the approximation, the resultant intersymbol interference (ISI), and the required transmitted energy. While the transversal designs are slightly more accurate, the frequency-sampling designs using six resonators have smaller ISI and energy values.
    Keywords: COMPUTERS
    Type: NASA-CR-120340 , BER-167-102
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  • 90
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    On-line diagnosis of unrestricted faults (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: A formal model for the study of on-line diagnosis is introduced and used to investigate the diagnosis of unrestricted faults. A fault of a system S is considered to be a transformation of S into another system S' at some time tau. The resulting faulty system is taken to be the system which looks like S up to time tau, and like S' thereafter. Notions of fault tolerance error are defined in terms of the resulting system being able to mimic some desired behavior as specified by a system similar to S. A notion of on-line diagnosis is formulated which involves an external detector and a maximum time delay within which every error caused by a fault in a prescribed set must be detected. It is shown that if a system is on-line diagnosable for the unrestricted set of faults then the detector is at least as complex, in terms of state set size, as the specification. The use of inverse systems for the diagnosis of unrestricted faults is considered. A partial characterization of those inverses which can be used for unrestricted fault diagnosis is obtained.
    Keywords: COMPUTERS
    Type: NASA-CR-139375
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  • 91
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    Development of sputtered techniques for thrust chambers, task 1 (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Filler materials proposed for use in the sputter fabrication regeneratively cooled thrust chambers were evaluated. Low melting castable alloys, CERROBEND. CERROCAST, and CERROTRU, slurry applied SERMETEL 481 and flame-sprayed aluminum were investigated as filler materials. Sputter deposition from a cylindrical cathode inverted magnestron was used to apply an OFHC copper closeout layer to filled OFHC copper ribbed-wall cylindrical substrates. The sputtered closeout layer structure was evaluated with respect to filler material contamination, predeposition machining and finishing operations, and deposition parameters. The application of aluminum by flame-spraying resulted in excessiver filler porosity. Though the outgassing from this porosity was found to be detrimental to the closeout layer structure, bond strengths in excess of 10,500 psi were achieved. Removal of the aluminum from the grooves was readily accomplished by leaching in a 7.0 molar solution of sodium hydroxide at 353 K. Of the other filler materials evaluated, CERROTRU was found to be the most suitable material with respect to completely filling the ribbed-wall cylinders and vacuum system compatibility. However, bond contamination resulted in low closeout layer bond strength with the CERROTRU filler. CERROBEND, CERROCAST, and SERMETEL 481 were found to be unacceptable as filler materials.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: NASA-CR-134629 , FR-6353-VOL-1
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  • 92
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    Holographic and ultrasonic detection of bond flaws in aluminum panels reinforced with boron-epoxy (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: An experimental investigation was made of the application of holographic interferometry to the nondestructive detection of unbonded areas (flaws) in bonded panels. Flaw detection results were compared with results obtained with an ultrasonic flaw detector. Holography, with panel deformation accomplished by a reduction in ambient pressure, is less sensitive for flaws beneath 5 and 10 plies of boron-epoxy than the ultrasonic method, though it does have its operational advantages. A process for the manufacture of bonded panels which incorporate known unbonded areas was also developed. The unbonded areas were formed without the use of foreign materials, which makes the method suitable for the construction of reference standards for bonded panels whenever needed for the proper setup of ultrasonic flaw-detection instruments.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: NASA-TN-D-7632 , L-9410
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  • 93
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    Design and fabrication of prototype system for early warning of impending bearing failure (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: A test program was conducted with the objective of developing a method and equipment for on-line monitoring of installed ball bearings to detect deterioration or impending failure of the bearings. The program was directed at the spin-axis bearings of a control moment gyro. The bearings were tested at speeds of 6000 and 8000 rpm, thrust loads from 50 to 1000 pounds, with a wide range of lubrication conditions, with and without a simulated fatigue spall implanted in the inner race ball track. It was concluded that a bearing monitor system based on detection and analysis of modulations of a fault indicating bearing resonance frequency can provide a low threshold of sensitivity.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: NASA-CR-120294 , MTI-74TR34
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  • 94
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    Rolling-element fatigue life of silicon nitride balls (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: The five-ball fatigue tester was used to evaluate silicon nitride as a rolling-element bearing material. Results indicate that hot-pressed silicon nitride running against steel may be expected to yield fatigue lives comparable to or greater than those of bearing quality steel running against steel at stress levels typical rolling-element bearing application. The fatigue life of hot-pressed silicon nitride is considerably greater than that of any ceramic or cermet tested. Computer analysis indicates that there is no improvement in the lives of 120-mm-bore angular--contact ball bearings of the same geometry operating at DN values from 2 to 4 million where hot-pressed silicon nitride balls are used in place of steel balls.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: NASA-TN-D-7794 , E-7219
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  • 95
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    Ferrographic analysis of wear debris from boundary lubrication experiments with a five-ring polyphenyl ether (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: The types of wear particles generated by a five-ring polyphenyl ether in boundary lubrication experiments in various atmospheres were determined by ferrographic analysis. The types of wear particles observed included cylindrical or rocklike organometallic debris, adhesive and cutting wear particles, and some spherical debris. Interpretations as to the mechanism of generation of the various types of particles are presented.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: NASA-TN-D-7804 , E-8007
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  • 96
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    Optimization of self-acting herringbone-grooved journal bearings for maximum stability (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Groove parameters were determined to maximize the stability of herringbone-grooved journal bearings. Parameters optimized were groove depth, width, length, and angle. Optimization was performed by using a small-eccentricity, infinite-groove analysis in conjunction with a previously developed Newton-Raphson procedure for bearings with the smooth member rotating or with the grooved member rotating at low compressibility numbers, and a newly developed vector technique for bearings with the grooved member rotating at high compressibility numbers. The design curves in this report enable one to choose the optimum bearing for a wide range of operating conditions. Compared with bearings optimized to maximize load capacity, bearings optimized for stability allow a thousandfold increase in bearing-supported mass in some cases before onset of instability, and lose no more than 77 percent of their load capacity in any case studied. Stability is much greater when the grooved member rotates.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: NASA-TN-D-7803 , E-7793
    Format: application/pdf
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  • 97
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    Development of an improved membrane for a vapor diffusion water recovery process (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Recovery of potable water from urine on manned space missions of extended duration was the objective of work aimed at the improvement of membrane performance for the vapor diffusion process (VDR). Kynar, Teflon, PVC, and polysulfone candidate membranes were evaluated from chemical, thermal, mechanical, and fabricating standpoints to determine their suitability for operation in the VDR pervaporation module. Pervaporation rates and other performance characteristics were determined in a breadboard pervaporator test rig. Kynar and Teflon membranes were demonstrated to be chemically stable at pervaporation temperatures in urine pretreated with chromic acid bactericide. The separation of the pervaporator and condenser modules, the use of a recirculating sweep gas to conduct pervaporate to the condenser, and the selection of a hollow fiber membrane configuration for pervaporator module design is recommended as a result of the investigation.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: NASA-CR-137544
    Format: application/pdf
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  • 98
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    The application of acoustic emission technique to fatigue crack measurement (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: The applicability of acoustic emission technique to measure fatigue cracks in aluminum alloy specimens was investigated. There are several variables, such as the metallurgical and the physical treatment of the specimen, that can affect the level of acoustic activity of a fatigue specimen. It is therefore recommended that the acoustic emission technique be supplemented by other nondestructive evaluation methods to obtain quantitative data on crack growth.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: NASA-TN-D-7695 , L-9530
    Format: application/pdf
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  • 99
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    Experimental evaluation of stresses in cylindrically hollow (drilled) balls (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: An experimental stress analysis was undertaken to evaluate stresses within cylindrically hollow (drilled) bearing balls proportioned for 40, 50, and 60 percent mass reductions. Strain gage rosettes were used to determine principal strains and stresses in the steel ball models statically loaded in various orientations. Results are reported for 127 mm OD balls under 44,500 N loads. Similitude considerations permit these results to be applied to calculate stresses in actual size drilled bearing balls proportioned to these mass reductions.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: NASA-CR-2439
    Format: application/pdf
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  • 100
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    Design, fabrication, assembly, and test of a liquid hydrogen acquisition subsystem (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: The development of a cryogenic fluid system to supply liquid hydrogen to a turbopump at flowrates up to 7.5 pounds per second for a period of approximately 5 seconds before refill, is discussed. Refill is accomplished in less than 10 seconds, during which a constant flowrate can be maintained to the pumps. Diagrams are provided to show the configuration of the system. Subsystem acceptance and functional tests, including acquisition subsystem expulsion, pressurization, and refill were performed. The tests included: (1) thermodynamic vent system operation, (2) warm-gas pressurization effects, (3) hydraulic pressure surge effects, (4) screen device operational limitations, (5) feedline vapor control, and (6) two-phase refill.
    Keywords: MACHINE ELEMENTS AND PROCESSES
    Type: NASA-CR-120447 , MDC-G5360
    Format: application/pdf
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