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  • Other Sources  (4,444)
  • SPACE RADIATION  (1,973)
  • AERODYNAMICS  (1,268)
  • MACHINE ELEMENTS AND PROCESSES  (1,203)
  • 1970-1974  (4,430)
  • 1940-1944  (8)
  • 1935-1939  (2)
  • 1925-1929  (1)
  • 1900-1904  (3)
Collection
  • Other Sources  (4,444)
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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    Possibility of using sources of vacuum ultraviolet irradiation to solve problems of space material science (1974)
    In:  CASI
    Details
    Publication Date: 2006-01-11
    Description: An urgent problem in space materials science is simulating the interaction of vacuum ultraviolet (VUV) of solar emission with solids in space conditions, that is, producing a light source with a distribution that approximates the distribution of solar energy. Information is presented on the distribution of the energy flux of VUV of solar radiation. Requirements that must be satisfied by the VUV source used for space materials science are formulated, and a critical evaluation is given of the possibilities of using existing sources for space materials science. From this evaluation it was established that none of the sources of VUV satisfies the specific requirements imposed on the simulator of solar radiation. A solution to the problem was found to be in the development of a new type of source based on exciting a supersonic gas jet flowing into vacuum with a sense electron beam. A description of this gas-jet source, along with its spectral and operation characteristics, is presented.
    Keywords: SPACE RADIATION
    Type: Space Res. in the Ukraine, No. 3 (NASA-TT-F-15537); p 102-123
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  • 10
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    Effect of small flares in the neutral component of secondary cosmic radiation (1974)
    In:  CASI
    Details
    Publication Date: 2006-01-11
    Description: The results are presented of an investigation of the effect of small flares, scale divisions 1 and 1(+), in the neutron component of secondary cosmic radiation from the data of neutron supermonitors at the stations of Kiev, Bukhta Tiksi, and Deep River. It is shown that flares of scale divisions 1 and 1(+) are accompanied by an effect in the neutron component amounting to about 0.4%. A mechanism is presented for calculating the outflow of particles accelerated in small flares, owing to diffusion across the magnetic field of a trap.
    Keywords: SPACE RADIATION
    Type: Space Res. in the Ukraine, No. 3 (NASA-TT-F-15537); p 77-85
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  • 11
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    Analysis of the nature of excessive cosmic radiation in the area of the Brazilian magnetic anomaly at altitudes 250-500km, from Kosmos-225 satellite data (1974)
    In:  CASI
    Details
    Publication Date: 2006-01-11
    Description: Results are presented from a study of the region of anomalous cosmic radiation in the area of the Brazilian magnetic anomaly at the altitudes 250-500 km, using data measurements taken on the Kosmos-225 satellite (14-29 June 1968). The existence of a stable intensity anomaly discovered in the experiments on the second and third Soviet spacecraft-satellites is confirmed. The total vector of the geomagnetic field at different altitudes was compared with isoline maps. An altitude profile of the South Atlantic anomaly of radiation intensity was obtained, using data from the same instrument. The nature of the anomalies in cosmic radiation intensity over the regions of negative magnetic anomalies is discussed.
    Keywords: SPACE RADIATION
    Type: Space Res. in the Ukraine, No. 3 (NASA-TT-F-15537); p 86-94
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  • 12
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    Acceleration of solar cosmic rays during chromospheric flares (1974)
    In:  CASI
    Details
    Publication Date: 2006-01-11
    Description: Using the Fokker-Planck equation, an examination is made of the acceleration of charged particles by fluctuational electric fields caused by the propagation of intense radio emission in the long-wave range. Correlation functions of electric fields near the boundary of plasma instability were computed. The interaction of charged particles with these fields is examined. It is shown that due to the interaction of particles with fluctuational fields, solar cosmic rays can be accelerated to energies of E=100 to 1000 MeV.
    Keywords: SPACE RADIATION
    Type: Space Res. in the Ukraine, No. 3 (NASA-TT-F-15537); p 69-76
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  • 13
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    Chromospheric flares and sudden commencements of geomagnetic storms (1974)
    In:  CASI
    Details
    Publication Date: 2006-01-11
    Description: A catalogue of flare activity was compiled during 1957-1967 (the solar activity cycle). By comparing all reliable SC during this period with chromospheric flares, the following conclusions are drawn; (1) There is no statistically significant correlation between SC and chromospheric flares. (2) The assumption that a shock wave propagates throughout the entire hemisphere is unjustified and contradicts the fact of recurrence of SC. (3) A statistically significant correlation was established between SC and chromospheric flares, that is, a relationship between a SC and the moment that a flare active region transits the Central Meridian. (4) SC are caused by shock waves or tangential discontinuities formed at the western boundary of the quasisteady directed corpuscular flux or at the boundary between sectors.
    Keywords: SPACE RADIATION
    Type: Space Res. in the Ukraine, No. 3 (NASA-TT-F-15537); p 61-68
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  • 14
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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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  • 15
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    Lifting-surface theory for a semi-infinite wing in oblique gust (1974)
    In:  Other Sources
    Details
    Publication Date: 2011-08-16
    Description: An unsteady lifting-surface theory is developed for the calculation of the airload on a semi-infinite-span thin wing in a compressible flow due to interaction with an oblique gust. By using the solutions obtained for a two-dimensional wing, the problem is formulated so that the unknown is taken to be the difference between the airload on the semi-infinite wing and that on a two-dimensional wing under the same gust conditions. Since this airload difference is nonzero only near the wing tip, the control points need be distributed in the tip region only; this significantly simplifies the numerical procedure. Results are presented for a wing with rectangular tip. The implication for noise and unsteady loads due to blade-vortex interaction for helicopter rotors is discussed.
    Keywords: AERODYNAMICS
    Type: AIAA Journal; 12; Dec. 197
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  • 16
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    Planetary entry aerothermodynamics. II - Computational analyses and flight experience (1974)
    In:  Other Sources
    Details
    Publication Date: 2011-08-16
    Description: Limitations concerning the possibility to simulate all the significant flow and thermal phenomena occurring during the entry of a space vehicle into a planetary atmosphere make it necessary to rely on computational analyses to obtain the required data for the design of the spacecraft needed for the NASA missions planned for the next two decades. 'Benchmark' computer programs concerned with complete, detailed, and accurate computational solutions of entry problems are considered along with programs representing engineering approximations for cases in which the accuracy provided by the benchmark programs is not needed. The information obtainable by computational analysis has to be supplemented by actual flight experience in order to meet the goals of the NASA entry-technology program. The individual space missions planned for the coming years are examined together with the possibilities for obtaining the data needed to satisfy the entry requirements in each case.
    Keywords: AERODYNAMICS
    Type: Astronautics and Aeronautics; 12; Dec. 197
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  • 17
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    Rigidity spectrum of z greater than or equal to 3 cosmic-ray nuclei in the range 4-285 GV and a search for cosmic antimatter (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: A measurement, using the magnetic emulsion spectrometer system, of the differential rigidity spectrum of Z greater than or equal to 3 nuclei of the galactic cosmic radiation is presented. The system was flown on Aug. 22, 1969, from Palestine, Texas. The instrument floated above 125,000 feet for eight hours. The data in the rigidity range 8-285 GV can be represented by a power-law spectrum in rigidity, J(rho) = A rho to the minus gamma power, with the exponent gamma = 2.6 plus or minus 0.10. The spectrum in the range 15-285 GV is also described by the same exponent, gamma = 2.6 plus or minus 0.25. The data below 8 GV cannot be described by the same power law without invoking solar modulation. A set of nonunique parameters for modulation are given. Upper limit for the fraction of antimatter in the rigidity range 4-125 GV is .005 with 95% confidence limit.
    Keywords: SPACE RADIATION
    Type: Astrophysical Journal; 192; Sept. 15
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  • 18
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    The distribution of cosmic rays in the galaxy and their dynamics as deduced from recent gamma ray observations (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: Data from SAS-2 on the galactic gamma ray line flux as a function of longitude is examined. It is shown that the gamma ray emissivity varies with galactocentric distance and is about an order of magnitude higher than the local value in a toroidal region between 4 and 5 kpc from the galactic center. This enhancement is accounted for in part by first-order Fermi acceleration, compression, and trapping of cosmic rays consistent with present ideas of galactic dynamics and galactic structure theory. Calculations indicate that cosmic rays in the 4 to 5 kpc region are trapped and accelerated over a mean time of the order of a few million years or about 2 to 4 times the assumed trapping time in the solar region of the galaxy on the assumption that only an increased cosmic ray flux is responsible for the observed emission. Cosmic ray nucleons, cosmic ray electrons, and ionized hydrogen gas were found to have a strikingly similar distribution in the galaxy according to both the observational data and the theoretical model discussed.
    Keywords: SPACE RADIATION
    Type: ESRO The Context and Status of Gamma Ray Astronomy; p 241-248
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  • 19
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    Observations of discrete gamma ray sources with SAS-2 (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: Compact gamma ray sources centered on the Crab nebula and the Vela X supernova remnant are considered. An excess in the galactic radiation was observed in both regions. Data indicate that a large fraction of this flux is pulsed. The excess from the Vela region could reflect either a large-scale galactic feature, such as a superposition of spiral arm segments, or it could be associated with the Vela supernova remnant. Low-energy gamma ray bursts were observed in the SAS-2 anticoincidence shielding.
    Keywords: SPACE RADIATION
    Type: ESRO The Context and Status of Gamma Ray Astronomy; p 273-277
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  • 20
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    Induction brazing at the Kennedy Space Center (1974)
    In:  Other Sources
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    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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  • 21
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    Cosmic electrons (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: The published literature on cosmic electrons is summarized. The primary and secondary sources of cosmic electrons are discussed, and the propagation of the electrons in the interstellar medium is studied with respect to energy loss mechanisms, age distributions, and spectral modifications during flight. Various portions of the electron and positron spectra are then considered in relation to problems of astrophysics. New information is presented on such topics as the origin of low-energy positrons, the decay kinematics of the pi-mu-e process, the application of age distributions for nuclear cosmic rays to cosmic electrons, and the possibility of nonidentical sources for cosmic electrons and protons.
    Keywords: SPACE RADIATION
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  • 22
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    Analysis of acoustic radiation in a jet flow environment (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: The analysis of sound fields from arbitrary source distributions in terms of Legendre and spherical Hankel functions is well known. The purpose of this paper is to extend this classical method of analysis to environments such as jet flows where flow and flow gradients are inherently present. The wave-equation governing the radiation of sound in such an environment is derived. The steady state flow and flow gradients in the axial and transverse directions appear as coefficients in the terms of the wave-equation. A semi-numerical method is used to solve the wave-equation in terms of modified spherical harmonics yielding the phase velocities and the directivities of an infinite set of modes. The directivity of each mode is obtained in terms of modified Legendre functions by numerical integration. Some results of these directivity and phase-velocity calculations are presented for a limited number of frequency and flow parameters. Both convective and shear refraction are shown to be important.
    Keywords: AERODYNAMICS
    Type: Journal of Sound and Vibration; 36; Sept. 8
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  • 23
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    Solar particles /observations, relationship to the sun acceleration, interplanetary medium/ (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: The major features of the propagation of flare particles in the interplanetary medium are discussed in terms of the classic well-behaved flare having unique impulsive injection and a smooth time profile. Topics include flare events, their frequency of occurrence, development of a typical event, energy spectra, proton and electron types, charge and isotopic composition, solar flares and particle accelerations, radio and X-ray observations, the Fermi mechanism, the betatron mechanism, acceleration models, plasma instabilities, two-stage acceleration, propagation mechanisms, the anisotropic stage, the diffusive stage, and the convection and energy loss stage.
    Keywords: SPACE RADIATION
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  • 24
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    Unified approach to aerodynamic sound generation in the presence of solid boundaries (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: A general equation governing aerodynamic sound generation in the presence of solid boundaries is derived. It is shown that all the theories in the literature appear as special cases of this general equation. Derived special equations for propeller and fan noise are likewise shown to be more general than the conventional equations in that they make allowance for variation in retarded time over the blade surfaces.
    Keywords: AERODYNAMICS
    Type: Acoustical Society of America; vol. 56
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  • 25
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    Impact testing on composite fan blades (1974)
    In:  Other Sources
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    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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  • 26
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    Sweet's mechanism in the solar wind (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: Sweet (1956, 1958) proposed a mechanism for the rapid, steady-state dissipation of a magnetic field in a resistive plasma. It is shown that Sweet's mechanism operates in the interplanetary medium near 1 AU in structures which Burlaga and Ness (1968) have identified and called D-sheets. The basic equations are considered of a specific mathematical model provided by Parker (1963) for the case of antiparallel fields and incompressible flow. The theoretical conclusions are related to interplanetary observations.
    Keywords: SPACE RADIATION
    Type: Astrophysical Journal; 191; Aug. 1
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  • 27
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    Automatic numerical generation of body-fitted curvilinear coordinate system for field containing any number of arbitrary two-dimensional bodies (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: A method for automatic numerical generation of a general curvilinear coordinate system with coordinate lines coincident with all boundaries of a general multi-connected region containing any number of arbitrarily shaped bodies is presented. With this procedure the numerical solution of a partial differential system may be done on a fixed rectangular field with a square mesh with no interpolation required regardless of the shape of the physical boundaries, regardless of the spacing of the curvilinear coordinate lines in the physical field, and regardless of the movement of the coordinate system. Numerical solutions for the lifting and nonlifting potential flow about Joukowski and Karman-Trefftz airfoils using this coordinate system generation show excellent comparison with the analytic solutions. The application to fields with multiple bodies is illustrated by a potential flow solution for multiple airfoils.
    Keywords: AERODYNAMICS
    Type: Journal of Computational Physics; 15; July 197
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  • 28
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    Analysis of propagation of waves of acoustic frequencies in curved ducts (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: The propagation of waves of acoustic frequencies in curved ducts of rectangular cross section is studied for the first four modes. The analysis makes use of Bessel functions of the order (n + 1/2) to construct curves of wavenumber in the duct versus imposed wavenumber and to determine the profile of vibrational velocities. A wide range of duct widths and unrestricted radii of curvature have been considered. The characteristics of motion in a bend are compared with propagation of waves in a straight duct, and important differences in the behavior of waves are noted.
    Keywords: AERODYNAMICS
    Type: Acoustical Society of America; vol. 56
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  • 29
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    Sealing of large leaks in high-vacuum systems subject to mechanical and thermal stresses (1974)
    In:  Other Sources
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    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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  • 30
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    Axial flow measurements in trailing vortices (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: A scanning laser Doppler velocimeter was used to measure the axial velocity defect in the cores of trailing vortices behind a lifting airfoil of rectangular planform. Data were obtained at several different angles of attack and downstream distances ranging from 30 to 1000 chord lengths. The test was designed to obtain continuous data from the near field into the far field while removing uncertainties associated with the interpretation of data obtained by the hydrogen bubble technique. The measured velocities of V sub x/U sub infinity are compared with those predicted. The agreement is remarkably good over the entire range of downstream distances, which supports the credibility of calculating axial velocities using the results of Moore and Saffman (1973).
    Keywords: AERODYNAMICS
    Type: AIAA Journal; 12; Aug. 197
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  • 31
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    The distribution of cosmic rays in the Galaxy and their dynamics as deduced from recent gamma-ray observations (1974)
    In:  Other Sources
    Details
    Publication Date: 2011-08-16
    Description: Recent data from SAS-2 on the galactic gamma-ray line flux as a function of longitude reveal a broad maximum in the gamma-ray intensity in the longitude region less than or equal to 30 deg. These data, when unfolded, imply that the low-energy (1 to 10 GeV) galactic cosmic-ray flux varies with galactocentric distance and is about an order of magnitude higher than the local value in a toroidal region between 4 and 5 kpc from the galactic center. It is further shown that this enhancement can be plausibly accounted for by first-order Fermi acceleration, compression, and trapping of cosmic rays consistent with present ideas of galactic dynamics and galactic structure theory. Calculations indicate that cosmic rays in the 4- to 5-kpc region are trapped and accelerated over a mean time of the order of a few million years or about 2 to 4 times the assumed trapping time in the solar region of the Galaxy.
    Keywords: SPACE RADIATION
    Type: Astrophysical Journal; 191; July 15
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  • 32
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    Aluminized alloy boosts turbine blade life (1974)
    In:  Other Sources
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    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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  • 33
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    Origin of QSO absorption lines (1974)
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    Publication Date: 2011-08-16
    Description: Consideration of the origin of the absorption lines in QSOs with observed absolute redshifts much less than the empirical values. As a possible alternative to the plasmoid mechanism for decreasing the relatively large possible macroscopic or bulk motions in QSO clouds, it is shown that certain large relative bulk motions in QSO clouds can be dissipated without the presence of strong magnetic fields and without large adiabatic expansions. The essence of the argument is that a cloud with convergent internal velocities can coalesce inelastically, because the internal kinetic energy can be dissipated and radiated away. There are thus indications that observed QSO absorption clouds may have their origin in clouds with internal velocities which are convergent.
    Keywords: SPACE RADIATION
    Type: Nature; 250; July 26
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  • 34
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    478-keV and 431-keV line emissions from alpha-alpha reactions (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Keywords: SPACE RADIATION
    Type: Astrophysical Journal; 191; July 1
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  • 35
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    1.0 arc second structure on the sun at 3.71 cm wavelength (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Keywords: SPACE RADIATION
    Type: Solar Physics; 36; June 197
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  • 36
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    Ionization equilibrium in soft X-ray-emitting solar flares (1974)
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    Publication Date: 2011-08-16
    Description: Studies of the 1.9-A line produced by highly ionized iron during a solar flare indicate that this emission occurs under conditions approaching a steady-state ionization equilibrium. Time-dependent and steady-state ionization equilibrium values are used for calculation of 1.9 A line fluxes per unit flare emission. The results are compared with those obtained by observations of some four solar flares, showing that the calculations from time-dependent equilibrium values approximate the observed line flux values with the same accuracy as the calculations from steady-state equilibrium values only when the electron densities are equal to or greater than 10 billion per cu cm.
    Keywords: SPACE RADIATION
    Type: Solar Physics; 36; June 197
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  • 37
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    Solar longitude dependence of some characteristics of type III radio bursts from metric to hectometric wavelengths (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: Using the observed data for metric and hectometric type III radio bursts, the dependence of burst characteristics on the solar longitude has been examined over a wide frequency range. It is found that there exists and east-west asymmetry for the extension of metric type III bursts into the hectometric wavelength range. In particular, hectometric bursts are rarely observed for solar flares associated with metric bursts east of 60 E solar longitude. Furthermore, for east longitudes, the low-frequency radio observations show a large dispersion in drift time interval.
    Keywords: SPACE RADIATION
    Type: Solar Physics; 36; May 1974
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  • 38
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    On helium-like 1s2l-1snl prime transitions in solar flare spectra (1974)
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    Publication Date: 2011-08-16
    Description: Expected wavelengths and intensities are computed for 1s2l-1snl prime transitions in helium-like ions of the abundant elements from oxygen to iron under coronal conditions. Probable observations of some of these lines in the spectra of solar flares are discussed, and attention is called to a possible reversal of singlet and triplet intensities as compared to laboratory observations.
    Keywords: SPACE RADIATION
    Type: Solar Physics; 36; May 1974
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  • 39
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    The Fokker-Planck coefficient for pitch-angle scattering of cosmic rays (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: For the case of homogeneous, isotropic magnetic field fluctuations, it is shown that most theories which are based on the quasi-linear and adiabatic approximations yield the same integral for the Fokker-Planck coefficient for the pitch-angle scattering of cosmic rays. For example, despite apparent differences, the theories due to Jokipii and to Klimas and Sandri yield the same integral. It is also shown, however, that this integral in most cases has been evaluated incorrectly in the past. For small pitch angles, the errors in previous evaluations are fortuitously of minor importance. For large pitch angles, however, these errors become more significant; and for pitch angles of 90 deg, the actual Fokker-Planck coefficient contains a delta function which has been overlooked in the past. The implications of these corrections on the possibility of relating cosmic-ray diffusion coefficients to observed properties of the interplanetary magnetic field are discussed.
    Keywords: SPACE RADIATION
    Type: Astrophysical Journal; 190; June 1
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  • 40
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    Vortex measurements behind a swept wing transport model (1974)
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    Publication Date: 2011-08-16
    Description: A backscatter laser Doppler velocimeter which simultaneously senses the axial and the tangential components of the velocity has been used to measure the velocity distributions in the near wake of a swept wing semispan transport model in a wind tunnel. The model configuration included nacelles, pylons, antishock bodies, and wing flaps which could be deflected 27 deg. Typical wake vortex velocity profiles are presented for the flaps-retracted and the flaps-deployed 27 deg configurations, respectively.
    Keywords: AERODYNAMICS
    Type: Journal of Aircraft; 11; June 197
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  • 41
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    Empirical solar proton model for orbiting spacecraft applications (1974)
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    Publication Date: 2011-08-16
    Description: An empirical model for energetic solar proton fluxes is presented. With this model the effects of such protons on geocentric space missions, to be flown during the next solar active period (1977-1983), and with orbits involving partial magnetospheric shielding, may be estimated. A synoptic background review is given, followed by a detailed discussion of the model's use, errors, uncertainties, and limitations, including sample calculations which demonstrate the application of specific or general project missions. Finally, for circular trajectories, percentage exposure maps are presented, depicting fractional mission times spent outside particular L shells as functions of orbit altitude and inclination.
    Keywords: SPACE RADIATION
    Type: IEEE Transactions on Aerospace and Electronic Systems; AES-10; July 197
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  • 42
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    Solar proton fluences for 1977-1983 space missions (1974)
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    Publication Date: 2011-08-16
    Description: The probability with which any given solar proton fluence level will be exceeded during a space mission is computed for mission to be flown during the active phase of the next solar cycle (1977-1983). This probability is a function of fluence level, proton energy threshold, and mission duration. Calculations are based on 1966-1972 data only. In estimating mission fluences, a distinction is made between ordinary and anomalously large events. Probable numbers of each type of event are estimated from Burrell's extension of Poisson statistics. Fluences of all anomalously large events are assumed to have a spectrum given by the August 1972 event, while fluences of the ordinary events are assumed to obey a log normal distribution.
    Keywords: SPACE RADIATION
    Type: Journal of Spacecraft and Rockets; 11; June 197
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  • 43
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    The anomalous abundance of cosmic-ray nitrogen and oxygen nuclei at low energies (1974)
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    Publication Date: 2011-08-16
    Description: Recent measurements using the Goddard-University of New Hampshire cosmic-ray telescope on the Pioneer 10 spacecraft have revealed an anomalous spectrum of nitrogen and oxygen nuclei relative to other nuclei such as He and C, in the energy range 3-30 MeV per nucleon. The intensity of nitrogen and oxygen nuclei is enhanced by a factor of up to 20 relative to their abundance in galactic or solar cosmic rays. It is argued that this is most likely a new extrasolar component of cosmic rays.
    Keywords: SPACE RADIATION
    Type: Astrophysical Journal; 187; Feb. 1
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  • 44
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    An upper limit on soft X-ray pulsations from the pulsar PSR 0833-45 (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: The Vela pulsar PSR 0833-45, located in the Vela X nebula, has the second shortest period of any of the known radio pulsars. Soft X-ray observations are described which place an upper limit of 0.3% on the pulsed fraction of the Vela pulsar relative to the flux from the entire Vela X Nebula, in the 0.5- to 1.0-keV energy band. The present results are about a factor of 7 below the value of 2% measured by Harnden and Gorenstein (1973) for the pulsed fraction relative to the flux from the Vela X Nebula.
    Keywords: SPACE RADIATION
    Type: Astrophysical Journal; 189; May 1
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  • 45
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    Friction and friction-generated temperature at a polymer-metal interface (1974)
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    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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  • 46
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    The helium component of solar wind velocity streams (1974)
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    Publication Date: 2011-08-16
    Description: Systematic variations of the properties of the helium constituent of the solar wind in the velocity streams are described. It is found that the helium abundance varies by about a factor of 2 as the stream is crossed. The velocity of the helium differs from that of the hydrogen by a few kilometers per second throughout much of the stream structure. This velocity difference is greatest immediately after the proton density peak passes, the helium velocity being typically 20 km/sec faster than the protons at that position in the stream. A sharp dip in the helium to proton temperature ratio is centered on the proton density peak. Although it appears reasonable that at least the velocity and temperature effects are due to the dynamic interactions of the two streams, it is not yet clear exactly what physical processes are directly involved in producing the effects described here.
    Keywords: SPACE RADIATION
    Type: Journal of Geophysical Research; 79; Mar. 1
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  • 47
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    Shock shapes of blunt bodies in hypersonic helium, air, and CO2 flows (1974)
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    Publication Date: 2011-08-16
    Description: A primary factor governing hypersonic flowfield characteristics of blunt vehicles entering planetary atmospheres is the normal shock density ratio. Hence, a means of duplicating or simulating the high density ratios experienced during planetary entry is needed. One facility having the capability of generating a range of hypersonic-hypervelocity flow conditions in arbitrary test gases is the expansion tube. Preliminary shock shape results obtained in the Langley 6-in. expansion tube at hypersonic conditions are presented. Normal shock density ratios from approximately 4 to 19 were generated using helium, air, and CO2 test gases at freestream velocities from 5 to 7 km/sec. Test models were a flat-faced cylinder and the Viking aeroshell.
    Keywords: AERODYNAMICS
    Type: AIAA Journal; 12; Mar. 197
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  • 48
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    Effects of heavy ions on electron temperatures in the solar corona and solar wind (1974)
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    Publication Date: 2011-08-16
    Description: The effects of the reduction in the thermal conductivity due to heavy ions on electron temperatures in the solar corona and solar wind are examined. Large enhancements of heavy ions in the corona appear to be necessary to give appreciable changes in the thermal gradient of the electrons. These enhancements, if they should occur, may contribute to the understanding of some low values of solar wind temperature measurements at 1 AU.
    Keywords: SPACE RADIATION
    Type: Journal of Geophysical Research; 79; Jan. 1
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  • 49
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    Some effects of diffusion on the flow of ions in the solar wind (1974)
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    Publication Date: 2011-08-16
    Description: The contribution of diffusive effects to the near equality of flow velocities of H+ and heavier ions of the solar wind at 1 AU is examined. Frictional drag on heavy ions from average solar wind fluxes of H+ appears to make an appreciable contribution to equalizing velocities. The frictional drag on H+ due to the presence of heavy ions may make an appreciable contribution to equalizing flow velocities, since compensating increases in coronal temperatures may be required in order to give solar wind velocities for H+. However, rather large enhancements of heavy ions near the sun appear to be required. If appreciable enhancements of heavy ions extend beyond about 2.5 solar radii, significant increases in heavy ion temperatures above H+ temperatures may be produced. This temperature difference may contribute to equalizing flow velocities and may contribute to the explanation of measured temperature differences at 1 AU between H+ and He++.
    Keywords: SPACE RADIATION
    Type: Journal of Geophysical Research; 79; Apr. 1
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  • 50
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    Computation of transonic flow about lifting wing-cylinder combinations (1974)
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    Publication Date: 2011-08-16
    Description: Some results are described for a lifting rectangular wing centrally located on a circular-cylindrical body. This simple configuration has been utilized in order to assess the merits of a mapping technique for wing-body configurations. The procedure employed makes use of a coordinate transformation to simplify specification of the surface boundary condition in the computation of the flow about the wing. The method can be extended to incorporate wing sweep, finite length body of noncircular cross section, and arbitrary wing placement; however, these extensions involve a considerable increase in complexity of the problem.
    Keywords: AERODYNAMICS
    Type: Journal of Aircraft; 11; Apr. 197
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  • 51
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    Some measurements of the attenuation of solar radiation during BOMEX (1974)
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    Publication Date: 2011-08-16
    Description: Measurements of the upward and downward flux of solar radiation in two broad wavelength bands defined by glass filters were made at height between about 300 and 12,000 m in the neighborhood of Barbados during the BOMEX experiment in the summer of 1969. These were examined on selected occasions, apparently cloudless, to determine the attenuation (absorption and upward scattering) that could not be attributed to atmospheric gases and must be considered to be caused by particles. Total particle absorption between the lowest and highest flight levels was found to be of order 5%, and upward scatter of order 1% of the incident radiation. Unexplained attenuation above the highest level was of order 2%. The attenuation attributed to particles was approximately the same magnitude as the geometrical cross section deduced by direct particle sampling on the same flights.
    Keywords: SPACE RADIATION
    Type: Applied Optics; 13; Mar. 197
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  • 52
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    Cosmic far ultraviolet background (1974)
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    Publication Date: 2011-08-16
    Description: The expected intensities of various possible components of the far ultraviolet background are discussed. It is concluded that existing results do not place interesting constraints on the density of the intergalactic medium (IGM). Current techniques and instrumentation for far ultraviolet astronomy are, however, sufficient to achieve vastly improved limits. New observations are required to determine whether the IGM can be detected in the far ultraviolet or whether the extragalactic component of the background is masked by radiation with a more local origin.
    Keywords: SPACE RADIATION
    Type: Nature; 247; Feb. 22
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  • 53
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    Solid state and fusion resistance spot welding of TD-NiCr sheet (1974)
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    Publication Date: 2011-08-16
    Keywords: MACHINE ELEMENTS AND PROCESSES
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  • 54
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    A vortex entrainment model applied to slender delta wings (1974)
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    Publication Date: 2011-08-16
    Description: A mathematical model of the vortex flow over a slender sharp-edged delta wing is proposed, and is shown to provide good agreement with the experiment. Although the technique requires experimental data in the form of the vortex core locations, it does account for the previously ignored mass entrainment of the vortex core.
    Keywords: AERODYNAMICS
    Type: AIAA Journal; 12; Jan. 197
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  • 55
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    Extraction of derivatives from flight data for several aircraft, using the LRC interactive computer system (1974)
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    Publication Date: 2011-08-16
    Description: Results are presented of a procedure for estimating stability and control parameters from flight data, by using maximum likelihood methods employing an interactive computer system, which was established at the NASA Langley Research Center. Problems encountered are discussed.
    Keywords: AERODYNAMICS
    Type: Parameter Estimation Tech. and Appl. in Aircraft Flight Testing; p 49-76
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  • 56
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    Identification of aircraft stability and control derivatives in the presence of turbulence (1974)
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    Publication Date: 2011-08-16
    Description: A maximum likelihood estimator for a linear system with state and observation noise is developed to determine stability and control derivatives from flight data obtained in the presence of turbulence. The formulation for the longitudinal short-period mode is presented briefly, including a special case that greatly simplifies the problem if the measurement noise on one signal is negligible. The effectiveness and accuracy of the technique are assessed by applying it first to simulated flight data, in which the true parameter values and state noise are known, then to actual flight data obtained in turbulence. The results are compared with data obtained in smooth air and with wind-tunnel data. The complete maximum likelihood estimator, which accounts for both state and observation noise, is shown to give the most accurate estimate of the stability and control derivatives from flight data obtained in turbulence. It is superior to the techniques that ignores state noise and to the simplified method that neglects the measurement noise on the angle-of-attack signal.
    Keywords: AERODYNAMICS
    Type: Parameter Estimation Tech. and Appl. in Aircraft Flight Testing; p 77-114
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  • 57
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    A comparison of two methods of extracting stability derivatives from flight test data (1974)
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    Publication Date: 2011-08-16
    Description: Two methods for extracting stability derivatives from flight data are compared. A modified Newton-Raphson quasilinearization minimization technique and a digital-analog (hybrid) matching technique were used to analyze the same data maneuvers obtained from two aircraft. About 70 maneuvers from an F-111E aircraft were analyzed over a Mach number range of 0.3 to 2.0 and an angle of attack range of 3 to 19 degrees. About 20 maneuvers were analyzed for the X-24A lifting body at Mach numbers of 0.5, 0.8, and 0.9, and an angle of attack range of 4 to 13 degrees. Stability derivatives were extracted from these maneuvers and the results from the two techniques, along with wind tunnel results, were compared.
    Keywords: AERODYNAMICS
    Type: NASA. Flight Res. Center Parameter Estimation Tech. and Appl. in Aircraft Flight Testing; p 43-48
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  • 58
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    Ultrasonic examination of welded joints of great thickness in mechanical equipment under pressure (1974)
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    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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    Influence of ultrasounds on electrolytic polishing (1974)
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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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  • 60
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    Coherent scattering of cosmic neutrinos (1974)
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    Publication Date: 2011-08-16
    Description: It is shown that cosmic neutrino scattering can be non-negligible when coherence effects previously neglected are taken into account. The coherent neutrino scattering cross section is derived and the neutrino index of refraction evaluated. As an example of coherent neutrino scattering, a detector using critical reflection is described which in principle can detect the low energy cosmic neutrino background allowed by the measured cosmological red shift.
    Keywords: SPACE RADIATION
    Type: Astronomy and Astrophysics; 37; 1, De; Dec. 197
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  • 61
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    Correlation for estimating vortex rotational velocity downstream dependence (1974)
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    Publication Date: 2011-08-16
    Description: Description of a correlation, derived from water tank measurements in the wake of wings towed under water, that makes it possible to predict the downstream distance behind an aircraft in flight where its trailing vortex will begin to decay. Comparisons of measured and predicted data are discussed.
    Keywords: AERODYNAMICS
    Type: Journal of Aircraft; 11; Nov. 197
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  • 62
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    Roll-up of aircraft trailing vortices using artificial viscosity (1974)
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    Publication Date: 2011-08-16
    Description: The artificial viscosity method of Kuwahara and Takami (1973) is used to calculate the roll-up of trailing vortices behind a number of practical aerodynamic configurations. Where possible, the results are compared for core location with available experimental data.
    Keywords: AERODYNAMICS
    Type: Journal of Aircraft; 11; Nov. 197
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  • 63
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    Search for optical emission from cosmic gamma-ray bursts (1974)
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    Publication Date: 2011-08-16
    Description: Long-exposure films are available for both times and regions of sky for several cosmic gamma-ray bursts. A visual magnitude of no more than 6 was set for optical emission from the well-observed May 14, 1972, event. The corresponding lower limit for the ratio of X-ray to optical energy flux in the burst is greater than 100. This may restrict solar-flare analogy models for the burst sources.
    Keywords: SPACE RADIATION
    Type: Astrophysical Journal; 192; Sept. 15
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  • 64
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    The origin of the diffuse background gamma radiation (1974)
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    Publication Date: 2011-08-16
    Description: Recent observations provided evidence for diffuse background gamma radiation extending to energies beyond 100 MeV, and evidence of isotropy and implied cosmological origin. Significant features in the spectrum of this background radiation were observed which provide evidence for its origin in nuclear processes in the early stages of big-bang cosmology, and connect these processes with the galaxy formation theory. A test of the theory is in future observations of the background radiation in the 100 MeK to 100 GeV energy range which are made with large orbiting spark-chamber satellite detectors. The theoretical interpretations of present data, their connection with baryon-symmetric cosmology and galaxy formation theory, and the need for future observations are discussed.
    Keywords: SPACE RADIATION
    Type: ESRO The Context and Status of Gamma Ray Astronomy; p 147-156
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    Progress in gamma ray burst astronomy (1974)
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    Publication Date: 2011-08-16
    Description: Spectral observations on nine of the eleven known cosmic gamma ray bursts detected from IMP-7 from late 1972 through 1973 are reported. All nine events were found to have average spectra ranging from 100 to 1100 keV. The hypothesis of a single greater than 100 keV average event spectrum for all gamma ray bursts (inferred from IMP-6 observations) was investigated. In addition to the mutual consistency of these 14 IMP events, all independently reported average event spectra fit the IMP-7 common spectrum. This observed lack of variability of the average event spectrum suggests that the production mechanism is tied to more rigidly fixed source parameters than most celestial or solar hard X-ray phenomena. Other characteristics of gamma ray bursts events, are discussed: a high-energy spectral tail with power-law index -2.5, a rising size spectrum from the earlier event rate, and a hint of clustering of event occurrence in time.
    Keywords: SPACE RADIATION
    Type: ESRO The Context and Status of Gamma Ray Astronomy; p 37-45
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  • 66
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    Gamma radiation from the Crab Nebula above 35 MeV (1974)
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    Publication Date: 2011-08-16
    Keywords: SPACE RADIATION
    Type: Nature; 251; Oct. 4
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    Cosmic rays - Astronomy with energetic particles (1974)
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    Publication Date: 2011-08-16
    Description: All nuclei in the periodic table of the elements, as well as electrons and positrons, are present in the stream of cosmic-ray particles. The cosmic-ray particles constitute the only sample of matter from outside the solar system which reaches the earth. Some of the most accurate knowledge of the extrasolar-element abundance distribution is based on the study of these particles. Observational data concerning the cosmic rays are discussed along with cosmic-ray sources, questions of particle interactions and propagation, the electron spectrum, and the significance of the positron component. The directions of cosmic ray research in the immediate future are also considered, giving attention to some fundamental questions which have not yet been answered.
    Keywords: SPACE RADIATION
    Type: Physics Today; 27; Oct. 197
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  • 68
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    The abundances of nuclei in the cosmic radiation (1974)
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    Publication Date: 2011-08-16
    Description: The relative abundances are treated as a consequence of processes in cosmic ray transport occurring during passage of the radiation through interstellar material at high velocity. Some of the subjects mentioned are nuclear fragmentation and the production of secondary nuclei, nuclear reactions, energy loss and nuclear decay, ionization, the range-energy relation and propagation variables, capture and loss of electrons, the propagation of nuclei, the transport equation, equilibrium solutions, energy-dependent path length distribution, exponential path length distributions, discrete spectra, sources, supernovae, and the origin of the abundances. The connection between the space-time features of the sources, the material traversed, and the effects of magnetic fields is established by describing the particle-field interaction as a diffusive or random-walk process.
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  • 69
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    High energy particles and quanta in astrophysics (1974)
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    Publication Date: 2016-03-07
    Description: The various subdisciplines of high-energy astrophysics are surveyed in a series of articles which attempt to give an overall view of the subject as a whole by emphasizing the basic physics common to all fields in which high-energy particles and quanta play a role. Successive chapters cover cosmic ray experimental observations, the abundances of nuclei in the cosmic radiation, cosmic electrons, solar modulation, solar particles (observation, relationship to the sun acceleration, interplanetary medium), radio astronomy, galactic X-ray sources, the cosmic X-ray background, and gamma ray astronomy. Individual items are announced in this issue.
    Keywords: SPACE RADIATION
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  • 70
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    Cosmic ray experimental observations (1974)
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    Publication Date: 2011-08-16
    Description: The current experimental situation in cosmic ray studies is discussed, with special emphasis on the development of new detector systems. Topics covered are the techniques for particle identification, energy measurements, gas Cerenkov counters, magnet spectrometers, ionization spectrometers, track detectors, nuclear emulsions, multiparameter analysis using arrays of detectors, the Goddard ionization spectrometer, charge spectra, relative abundances, isotope composition, antinuclei in cosmic rays, electrons, the measurement of cosmic ray arrival directions, and the prehistory of cosmic rays.
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  • 71
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    A discussion of interplanetary postshock flows with two examples (1974)
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    Publication Date: 2011-08-16
    Description: Plasma and magnetometer observations of two types of flare-associated shock flows are described and compared with present models. One type represents a class of flows in which the shock is followed by a stream and separated from it by a region in which density, temperature, and speed decrease monotonically. Neither the blast wave model nor the two-stage model, in which the stream and the shock are attributed to the same flare, can quantitatively describe this class. The other type is characterized by a complex region between the shock and the following stream, which has many discontinuities and fluctuations but in which there is no increase in helium concentration. This class of event is not describable in terms of the conventional pictures presented, for example, by Hundhausen (1972). These two types of flow can be distinguished by using ground magnetograms, since the first type shows no sudden impulses following the shock, whereas the second type shows many.
    Keywords: SPACE RADIATION
    Type: Journal of Geophysical Research; 79; June 1
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  • 72
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    Influence of ablation impurities on blunt body re-entry ionization (1974)
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    Publication Date: 2011-08-16
    Description: Electron density profiles which include the effect of an ablated sodium impurity were computed for the boundary layer on a blunt-nosed body re-entering the atmosphere at 7.62 km/sec. Profiles are computed from the nose to a distance of four diameters along the RAM C-payload. A finite-difference, laminar, nonequilibrium chemistry boundary-layer program was used. Comparison of theory with S-band diagnostic antenna results, electron concentration deduced from X- and C-band attenuation data, and Langmuir probe data at several different aft body locations show that agreement is good at high altitude. At the lower altitudes there is disagreement between theory and S-band antenna data where the apparent discrepancy is attributed to the three-body recombination rate constant used for deionization of sodium coupled with the effect of angle of attack.
    Keywords: AERODYNAMICS
    Type: AIAA Journal; 12; June 197
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  • 73
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    Possible evidence for structured acceleration of cosmic rays on a galactic scale from recent gamma-ray observations (1974)
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    Publication Date: 2011-08-16
    Description: Recent data from SAS-2 on the galactic gamma-ray line flux as a function of longitude reveal a broad maximum in the region below 30 deg. These data, as unfolded here, imply that the low-energy (1-10 GeV) galactic cosmic-ray flux varies with the radial distance from the galactic center and is about an order of magnitude higher than the local value in a toroidal region for radial distances between 4 and 5 kpc. We further show that this enhancement can be plausibly accounted for by Fermi acceleration and compression caused by a hydrodynamic shock driven by the expanding gas in the 3-kpc arm and invoked in some versions of galactic structure theory.
    Keywords: SPACE RADIATION
    Type: Astrophysical Journal; 188; Mar. 1
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  • 74
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    Monitoring the presence of foreign bodies in the equipment (1974)
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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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  • 75
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    Process for manufacturing slit collimators (1974)
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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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  • 76
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    Method of applying a mirror reflecting layer to instrument parts (1974)
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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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  • 77
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    Process of manufacturing small-module gears with internal coupling (1974)
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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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  • 78
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    Process of manufacturing grids from wire less than 0.025 MM in diameter by the galvanic growth method (1974)
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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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  • 79
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    Prospective areas in the production technology of scientific equipment for space research (1974)
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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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  • 80
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    Servosystem with an undulatory reducing gear (1974)
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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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  • 81
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    Solar flux and its variations (1974)
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    Publication Date: 2011-08-16
    Description: Current knowledge of the electromagnetic solar spectrum and radiant energy output for conditions of quiet and active sun is summarized. Discussed are temporal behavior and occurrence of solar phenomena such as active regions, calcium plages and flares, X-rays, UV and other energetic emissions, and their relationships to 11- and 22-year solar cycles.
    Keywords: SPACE RADIATION
    Type: NASA. Goddard Space Flight Center Possible Relationships between Solar Activity and Meteorol. Phenomena; p 143-187
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  • 82
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    A possible correlation between maxima of the far ultraviolet solar irradiance and central meridian passages of solar magnetic sector boundaries (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: Satellite observations of the sun over almost five years have shown that principally two UV active longitudes have persisted over a significant portion. A comparison between the position of solar magnetic sector boundaries and UV enhancements of the sun indicates that the UV maxima tend to occur near the times when a solar sector boundary is near central meridian. An estimate of the magnitude of the variable UV solar energy input into the atmosphere resulting from the rotation of active solar longitudes is that for wavelengths less than 175 nm and down to H. Lyman-alpha it exceeds the annual variation, whereas at longer wavelengths it is less. The total observed peak-to-peak variation in the UV irradiance from 120 to 300 nm over a solar rotation is typically at least 230 ergs/sq cms.
    Keywords: SPACE RADIATION
    Type: Possible Relationships between Solar Activity and Meteorol. Phenomena; p 116-121
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  • 83
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    The particle background observed by the X-ray detectors onboard Copernicus (1974)
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    Publication Date: 2011-08-16
    Description: The design and characteristics of low energy detectors on the Copernicus satellite are described. The functions of the sensors in obtaining data on the particle background. The procedure for processing the data obtained by the satellite is examined. The most significant positive deviations are caused by known weak X-ray sources in the field of view. In addition to small systemic effects, occasional random effects where the count rate increases suddenly and decreases within a few frames are analyzed.
    Keywords: SPACE RADIATION
    Type: NASA. Goddard Space Flight Center Proc. of the Workshop on Electron Contamination in X-ray Astronomy Expt.; 12 p
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  • 84
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    Geomagnetic background events observed by Uhuru (1974)
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    Publication Date: 2011-08-16
    Description: Problems due to sporadic background events observed by Uhuru (Small Astronomy Satellite - A) do not compromise the study of discrete X-ray sources. Nevertheless, direct particle effects and auroral type X-ray events in the atmosphere may occasionally occur. Therefore, even on the geomagnetic equator, an experiment must be prepared to recognize and eliminate such events when the ultimate level of sensitivity is desired. The test equipment contained in the satellite and the orbital mechanics of Small Astronomy Satellite - A are described. The sporadic events which were observed by the satellite are analyzed.
    Keywords: SPACE RADIATION
    Type: NASA. Goddard Space Flight Center Proc. of the Workshop on Electron. Contamination in X-ray Astronomy Expt.; 18 p
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  • 85
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    Electron contamination in a mid-latitude soft X-ray astronomy experiment during an intense magnetic storm (1974)
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    Publication Date: 2011-08-16
    Description: A large area X-ray sky survey payload was launched from White Sands Missile Range (106 deg W 32 deg N) on 1 Nov. 1972 at 0530 hours U.T. The launch time coincided with intense geomagnetic activity (3 hour K sub p index = 8) following a solar flare. The data have been analyzed to determine possible contamination of X-ray data by large fluxes of low energy electrons that can precipitate down to low altitudes during magnetic storms. There is clear evidence in the data for low energy electrons of 10 - 50 keV contributing appreciably at about 200 km altitude in the 1 - 10 keV X-ray energy channels of the proportional counters used for the X-ray observations. The McIlwain parameters L and B for this altitude at White Sands are 1.25 and 0.46G, respectively.
    Keywords: SPACE RADIATION
    Type: NASA. Goddard Space Flight Center Proc. of the Workshop on Electron Contamination in X-ray Astronomy Expt.; 21 p
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  • 86
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    AE-LEE measurements at low and mid latitude (1974)
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    Publication Date: 2011-08-16
    Description: Shortly after the Low Energy Electron Experiment (LEE) on the Atmosphere Explorer-C was turned on following launch, an unexpected phenomenon was encountered at mid-latitudes, a counting rate was acquired with one maximum per roll. Recent analysis shows that these counting rates occur when the detectors are looking in the ram direction of the spacecraft and the spacecraft is near perigee, and are indeed not due to properly analyzed charged particles. After showing the probable cause of these counting rates, some upper limits to true fluxes at low altitudes in the energy range 200 eV to 25 keV from the LEE experiment are shown. OGO-4 data taken at mid-latitudes are included.
    Keywords: SPACE RADIATION
    Type: Proc. of the Workshop on Electron Contamination in X-ray Astronomy Expt.; 14 p
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  • 87
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    Quasitrapped electrons in the low L region. Preliminary results of a rocket observation on 22 January 1972 (1974)
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    Publication Date: 2011-08-16
    Description: Suprathermal electrons in the energy range 5 - 100 keV were measured with thin-window proportional counters on board a sounding rocket. The flux of the electrons was found to increase with altitude in the range .100 - 550 km, corresponding to L = 1.15 - 1.22, the angular distribution to be peaked in the direction perpendicular to the geomagnetic line of force, and the energy to be represented by a power law.
    Keywords: SPACE RADIATION
    Type: NASA. Goddard Space Flight Center Proc. of the Workshop on Electron Contamination in X-ray Astronomy Expt.; 12 p
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  • 88
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    Effectiveness of solid lubricant coatings for friction in hard vacuum (10-9 tor) (1974)
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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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  • 89
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    Influence of low temperatures of friction and wear (1974)
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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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  • 90
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    Study of the possibility of using solar radiant energy for welding and brazing metals (1974)
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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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  • 91
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    Asperity lubrication and cavitation in face seals (1974)
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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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  • 92
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    Some after-dinner reflections on system identification (1974)
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    Publication Date: 2011-08-16
    Description: The growth of the field of system identification is discussed along with changes in methodology which have taken place in recent years. The similarity between pattern recognition and system identification is pointed out, involving the modelling in the latter and the feature selection problem in the former. It is stated that once a model is formulated, including the disturbances and measurement errors, the parameter finding can be formulated as a statistical estimation problem. The various techniques and their application are discussed.
    Keywords: AERODYNAMICS
    Type: NASA. Flight Res. Center Parameter Estimation Tech. and Appl. in Aircraft Flight Testing; p 381-385
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  • 93
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    Systems identification - reprise and projections (1974)
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    Publication Date: 2011-08-16
    Description: A state-of-the-arts review is given for the field of system identification. Progress in the field is traced from the early models of dynamic systems by Sir Isaac Newton up to the present day use of advanced techniques for numerous applications.
    Keywords: AERODYNAMICS
    Type: Parameter Estimation Tech. and Appl. in Aircraft Flight Testing; p 375-379
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  • 94
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    A new criterion for modeling systems (1974)
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    Publication Date: 2011-08-16
    Description: The criterion that is proposed is an expected value of the mean square response error as an alternative to testing a model against new data. Modeling with respect to this new criterion does not change the estimate for a given model format from a maximum likelihood estimate or mean square response error estimate. The new criterion does, however, provide a means of comparing models with different formats and varying complexity. A numerical example is used to illustrate the application of the proposed criteria and the problem of searching for the best model. For all but the most trivial system identification problems, it is shown that a prohibitive number of combinations of terms of the model must be investigated to ensure the final model is best.
    Keywords: AERODYNAMICS
    Type: Parameter Estimation Tech. and Appl. in Aircraft Flight Testing; p 291-313
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  • 95
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    Effects of flight instrumentation errors on the estimation of aircraft stability and control derivatives (1974)
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    Publication Date: 2011-08-16
    Description: An error analysis program based on an output error estimation method was used to evaluate the effects of sensor and instrumentation errors on the estimation of aircraft stability and control derivatives. A Monte Carlo analysis was performed using simulated flight data for a high performance military aircraft, a large commercial transport, and a small general aviation aircraft for typical cruise flight conditions. The effects of varying the input sequence and combinations of the sensor and instrumentation errors were investigated. The results indicate that both the parameter accuracy and the corresponding measurement trajectory fit error can be significantly affected. Of the error sources considered, instrumentation lags and control measurement errors were found to be most significant.
    Keywords: AERODYNAMICS
    Type: Parameter Estimation Tech. and Appl. in Aircraft Flight Testing; p 261-280
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  • 96
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    Nonlinear parameter identification: Ballistic range experience applicable to flight testing (1974)
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    Publication Date: 2011-08-16
    Description: The parameter identification scheme being used is a differential correction least squares procedure (Gauss-Newton method). The position, orientation, and derivatives of these quantities with respect to the parameters of interest (i.e., sensitivity coefficients) are determined by digital integration of the equations of motion and the parametric differential equations. The application of this technique to three vastly different sets of data is used to illustrate the versatility of the method and to indicate some of the problems that still remain.
    Keywords: AERODYNAMICS
    Type: Parameter Estimation Tech. and Appl. in Aircraft Flight Testing; p 191-195
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  • 97
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    On particle motion in an electric welding arc treated with sonic or ultrasonic oscillations (1974)
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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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  • 98
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    Cracking and reformation of saturated hydrocarbons by ultrasound in the presence of water (1974)
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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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  • 99
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    Contributions to the use of macrosounds for boiler decrusting (1974)
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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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  • 100
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    Contributions to study of the stability of the electric welding arc under the action of acoustic pressure (1974)
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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
    Format: text
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