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  • General Chemistry  (13.687)
  • SPACE RADIATION  (2.645)
  • Cell & Developmental Biology  (2.184)
  • BIOSCIENCES  (2.136)
  • STRUCTURAL MECHANICS  (2.018)
  • FLUID MECHANICS  (1.814)
  • COMMUNICATIONS
  • 1970-1974  (13.460)
  • 1960-1964  (7.929)
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  • 1
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    Space and man (1974)
    In:  CASI
    Details
    Publikationsdatum: 2006-01-11
    Beschreibung: The effects of man's entry into space on changes in economics and technology, politics and law, science, philosophy, and art are considered. A single world economy, extracting from the natural resources of the moon and other cosmic bodies raw materials and energy, will avoid terrestrial limitations and improve society by eliminating the inequalities of economic and social status. However, a spacecraft for interplanetary travel require thermonuclear engines that achieve an escape velocity of 0.1 times the speed of light in order to allow an astronaut stellar expedition corresponding to the active life of a single generation.
    Schlagwort(e): BIOSCIENCES
    Materialart: Inhabited Space, Pt. 2 (NASA-TT-F-820); p 128-134
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  • 2
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    Radio communications with extra-terrestrial civilizations (1974)
    In:  CASI
    Details
    Publikationsdatum: 2006-01-11
    Beschreibung: Communications between civilizations within our galaxy at the present level of radio engineering is possible, although civilizations must begin to search for each other to achieve this. If an extra-terrestrial civilization possessing a technology at our level wishes to make itself known and will transmit special radio signals to do this, then it can be picked up by us at a distance of several hundreds of light years using already existing radio telescopes and specially built radio receivers. If it wishes, this civilization can also send us information without awaiting our answer.
    Schlagwort(e): COMMUNICATIONS
    Materialart: Inhabited Space, Pt. 2 (NASA-TT-F-820); p 79-82
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  • 3
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    Detection of life in space (1974)
    In:  CASI
    Details
    Publikationsdatum: 2006-01-11
    Beschreibung: The selection of spacecraft experiments and equipment to detect extraterrestrial life outside earth centers on observations of chemical compounds similar to amino acids and proteins, on signs of metabolism in the form of nutrient absorption, and life form impressions in fossiles or signs of civilization.
    Schlagwort(e): BIOSCIENCES
    Materialart: Inhabited Space, Pt. 2 (NASA-TT-F-820; p 42-52
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  • 4
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    Space psychology (1974)
    In:  CASI
    Details
    Publikationsdatum: 2006-01-11
    Beschreibung: Psychological selection of astronauts considers mental responses and adaptation to the following space flight stress factors: (1) confinement in a small space; (2) changes in three dimensional orientation; (3) effects of altered gravity and weightlessness; (4) decrease in afferent nerve pulses; (5) a sensation of novelty and danger; and (6) a sense of separation from earth.
    Schlagwort(e): BIOSCIENCES
    Materialart: Inhabited Space, Pt. 2 (NASA-TT-F-820); p 29-41
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  • 5
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    Life in space (1974)
    In:  CASI
    Details
    Publikationsdatum: 2006-01-11
    Beschreibung: Biotechnological aspects of manned space flight are reviewed and the basic biological problems of training and sustaining man in interplanetary flights are elaborated.
    Schlagwort(e): BIOSCIENCES
    Materialart: Inhabited Space, Pt. 2 (NASA-TT-F-820); p 17-28
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  • 6
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    Noise and vibration level reduction by covering metal structures with layers of damping materials (1974)
    In:  CASI
    Details
    Publikationsdatum: 2006-01-11
    Beschreibung: One of the most important methods of reducing the noise and vibration level is the damping of the secondary sources, such as metal plates, often used in vehicle structures, by means of covering materials with high internal viscosity. Damping layers are chosen at an optimum thickness corresponding to the frequency and temperature range in which a certain structure works. The structure's response corresponding to various real situations is analyzed by means of a measuring chain including electroacoustical or electromechanical transducers. The experimental results provide the dependence of the loss factor and damping transmission coefficient as a function of the damping layer thickness or of the frequency for various viscoelastic covering materials.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 246-253
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  • 7
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    The Coanda effect in gas-dynamic noise control (1974)
    In:  CASI
    Details
    Publikationsdatum: 2006-01-11
    Beschreibung: The principle types of silencers are discussed for gas dynamic noise of free steam and gas expansions, as well as the results of research in gas dynamics of jets and applied acoustics. Gas dynamic noise attenuation by means of the Coanda effect is due to fluid decompression in a Coanda ejector of the external type, where a structural change takes place in the acoustic frequency spectrum and in its direction, as well as a substantial decrease in the fluid's velocity, temperature and concentration. This process is continued in the second phase with absorption of the acoustic waves by means of an active structure.
    Schlagwort(e): FLUID MECHANICS
    Materialart: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 143-149
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  • 8
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    Vibration and recoil control of pneumatic hammers (1974)
    In:  CASI
    Details
    Publikationsdatum: 2006-01-11
    Beschreibung: Vibration sources are described for pneumatic hammers used in the mining industry (pick hammers), in boiler shops (riveting hammers), etc., bringing to light the fact that the principal vibration source is the variation in air pressure inside the cylinder. The present state of the art of vibration control of pneumatic hammers as it is practiced abroad, and the solutions adopted for this purpose, are discussed. A new type of pneumatic hammer with a low noise and vibration level is presented.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 79-84
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  • 9
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    Vibration control in forge hammers (1974)
    In:  CASI
    Details
    Publikationsdatum: 2006-01-11
    Beschreibung: Special measures are discussed for calculating, designing and executing a forge hammer foundation, so that the vibrations that occur during its working will not be transmitted to neighboring machinery, workrooms and offices. These vibrations are harmful to the workers near the forge hammer.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 73-78
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  • 10
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    Experimental determination of the vibration level in 5,100 kW electric locomotive assemblies (1974)
    In:  CASI
    Details
    Publikationsdatum: 2006-01-11
    Beschreibung: Because of the high vibration level occurring during the running of electric locomotives, mechanical defects occur in the control mechanisms of auxiliary services. This fact has given rise to the necessity of determining the values of these vibrations in electric locomotives during their running. Measurements were conducted on the Craiova-Drobeta-Turnu Severin line, and measures to reduce the vibration level in electric locomotives were instituted.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 50-54
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  • 11
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    Random vibrations of linear viscoelastic beams with lumped masses (1974)
    In:  CASI
    Details
    Publikationsdatum: 2006-01-11
    Beschreibung: A method is presented of determining the mean square transversal deflection of an isotropic and homogeneous linear viscoelastic beam having a certain number of lengthwise distributed lumped masses. It is assumed that the beam is acted upon by a stationary random process uniformly distributed along the beam. The method is useful in vibration level control by means of additional lumped masses.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 36-42
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  • 12
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    Random vibrations of quadratic damping systems (1974)
    In:  CASI
    Details
    Publikationsdatum: 2006-01-11
    Beschreibung: An oscillating system with quadratic damping subjected to white noise excitation is replaced by a nonlinear, statistically equivalent system for which the associated Fokker-Planck equation can be exactly solved. The mean square responses are calculated and the optimum damping coefficient is determined with respect to the minimum mean square acceleration criteria. An application of these results to the optimization of automobile suspension damping is given.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 29-35
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  • 13
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    The response of many-storied structures under seismic actions (1974)
    In:  CASI
    Details
    Publikationsdatum: 2006-01-11
    Beschreibung: A seismic action which is characterized by the acceleration function of the seismic motion is analyzed. The equations of motion in the direction of the seismic action are determined for a completely rigid ground and for a ground with linear deformability characteristics (rotation deformability). The equation for the rotation motion is derived by considering elastic and viscoelastic properties of the foundation ground. The differential equations are written by treating the mechanical model of a many-storied structure as a fixed vertical beam with a uniformly distributed mass as well as with concentrated masses on each floor.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 43-49
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  • 14
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    Insulation of nonlinear and random vibrations in the mining industry (1974)
    In:  CASI
    Details
    Publikationsdatum: 2006-01-11
    Beschreibung: The insulation of nonlinear and random vibrations is considered for some ore preparing and sorting implements: rotary crushers, resonance screens, hammer mills, etc. The appearance of subharmonic vibrations is analyzed, and the conditions for their appearance are determined. A method is given for calculating the insulation of these vibrations by means of elastic elements made of rubber. The insulation of the random vibrations produced by Symons crushers is calculated by determining the transmissability and deformation of the insulation system for a narrow band random response.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 22-28
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  • 15
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    A mathematical model for storied buildings subjected to automatic loom stresses (1974)
    In:  CASI
    Details
    Publikationsdatum: 2006-01-11
    Beschreibung: Expressions are derived for the displacements of a many storied building subjected to the action of classical weaving looms located at different levels of the building. The building is regarded as a vertical fixed beam with a uniformly distributed mass as well as concentrated masses at each level. The calculation relations are obtained on the assumption of harmonic variation of the forces acting at each level as well as the assumption of narrow band stationary random excitatory forces.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 15-21
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  • 16
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    Study of vibrations produced by a vibrating beam used for vibrating concretes (1974)
    In:  CASI
    Details
    Publikationsdatum: 2006-01-11
    Beschreibung: For compacting concretes in building, vibrating beams are used. The vibrations are generated by inertial vibrators, and the beam is normally displaced by the operator by means of a handle that is elastically fastened to the beam by means of rubber pads. Considered are vibrations transmitted to the operator, taking into account the beam's shock vibration motions. The steady state motion of a dynamic beam pattern is studied, and results of experimental tests with existing equipment are presented.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 9-14
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  • 17
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    Intermediate memory devices (1974)
    In:  CASI
    Details
    Publikationsdatum: 2006-01-11
    Beschreibung: Several methods of transfer and processing of data whose practical implementation requires operational memory devices are described. Devices incorporating multistable elements are proposed and their main parameters are given. The possibility of using the proposed devices for storing information for transmission in space radio communications channels is examined.
    Schlagwort(e): COMMUNICATIONS
    Materialart: Space Res. in the Ukraine, No. 3 (NASA-TT-F-15537); p 155-162
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  • 18
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    Possibility of using sources of vacuum ultraviolet irradiation to solve problems of space material science (1974)
    In:  CASI
    Details
    Publikationsdatum: 2006-01-11
    Beschreibung: 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.
    Schlagwort(e): SPACE RADIATION
    Materialart: Space Res. in the Ukraine, No. 3 (NASA-TT-F-15537); p 102-123
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  • 19
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    Effect of small flares in the neutral component of secondary cosmic radiation (1974)
    In:  CASI
    Details
    Publikationsdatum: 2006-01-11
    Beschreibung: 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.
    Schlagwort(e): SPACE RADIATION
    Materialart: Space Res. in the Ukraine, No. 3 (NASA-TT-F-15537); p 77-85
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  • 20
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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
    Publikationsdatum: 2006-01-11
    Beschreibung: 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.
    Schlagwort(e): SPACE RADIATION
    Materialart: Space Res. in the Ukraine, No. 3 (NASA-TT-F-15537); p 86-94
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  • 21
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    Acceleration of solar cosmic rays during chromospheric flares (1974)
    In:  CASI
    Details
    Publikationsdatum: 2006-01-11
    Beschreibung: 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.
    Schlagwort(e): SPACE RADIATION
    Materialart: Space Res. in the Ukraine, No. 3 (NASA-TT-F-15537); p 69-76
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  • 22
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    Chromospheric flares and sudden commencements of geomagnetic storms (1974)
    In:  CASI
    Details
    Publikationsdatum: 2006-01-11
    Beschreibung: 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.
    Schlagwort(e): SPACE RADIATION
    Materialart: Space Res. in the Ukraine, No. 3 (NASA-TT-F-15537); p 61-68
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  • 23
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    Electromagnetic processes in the atmosphere of pulsars (1974)
    In:  CASI
    Details
    Publikationsdatum: 2006-01-11
    Beschreibung: The work consists of two parts. The first deals with the fine structure of radio pulses. Based on kinetic theory, processes occurring in the plasma shell of a pulsar when external electromagnetic radiation is present are investigated. It is shown that electromagnetic waves cause electrons to drift relative to ions, and initiate longitudinal oscillations. A dispersion equation describing the longitudinal oscillations in magnetized plasma is derived. Conditions for excitation of oscillations are found. Correlation functions of electron density are calculated, along with the coefficients of electromagnetic wave scattering. It is shown that variations in the amplitude of pulsar pulses are associated with scintillations caused by fluctuations in the plasma electron density. The second part of the study presents a mechanism for the radio emission of pulsars. The model of a rotating and a pulsating star, a neutron star with dipolar or more complex magnetic field, is examined.
    Schlagwort(e): COMMUNICATIONS
    Materialart: Space Res. in the Ukraine, No. 3, (NASA-TT-F-15537); p 44-53
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  • 24
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    The tropospheric calibration model for Mariner Mars 1971 (1974)
    In:  CASI
    Details
    Publikationsdatum: 2006-01-11
    Beschreibung: The effects of the troposphere on arrival time, range, and range rate measurement of radio signals propagating from spacecraft are examined. A tropospheric calibration model which takes into account seasonal variations, various elevations, and apparent location changes was developed. A comparison was made of the effects before and after calibration. Without calibration, a 16-m change in the distance off the spin axis, is induced for a 10-deg minimum elevation symmetrical pass. Even after calibration with the old model, the error in spin axis is still greater than 1 m. Calibration results and estimated uncertainties of the model are given in tabular form. Test results also show that the model met the required accuracy for the Mariner Mars 1971 mission.
    Schlagwort(e): COMMUNICATIONS
    Materialart: Tracking System Analytic Calibration Activities for the Mariner Mars 1971 Mission; p 61-76
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  • 25
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    Stresses in dome-shaped shells of revolution with discontinuities at the apex (1974)
    In:  CASI
    Details
    Publikationsdatum: 2006-04-02
    Beschreibung: Asymptotic solutions of Novozhilov's equations of shells of revolution are derived for axisymmetric and first harmonic loadings. The solutions obtained are valid throughout the shallow and nonshallow regions. Stresses in dome shaped shells of revolution with a discontinuity in the form of a circular hole, a circular rigid insert, or a nozzle at the apex have been investigated. Numerical results are obtained for spheres, ellipsoids, and paraboloids, containing a discontinuity under a internal pressure and moment. Curves depicting stress distributions are given. The influence of three types of discontinuity on the stresses of the shells is also given.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: Multivariant Function Model Generation; 118 p
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  • 26
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    Current structural vibration problems associated with noise (1974)
    In:  CASI
    Details
    Publikationsdatum: 2011-10-14
    Beschreibung: As the performance of aerospace vehicles has increased, the noise generated by the propulsion system and by the passage of the vehicle through the air has also increased. Further increases in performance are now underway for space vehicles such as the space shuttle vehicle and for short distance takeoff and landing (STOL) aircraft, and are being planned for supersonic aircraft. The flight profiles and design features of these high-performance vehicles are reviewed and an estimate made of selected noise-induced structural vibration problems. Considerations for the prevention of acoustic fatigue, noise transmission, and electronic instrument malfunction are discussed.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: AGARD Noise Mech.; 16 p
    Format: text
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  • 27
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    Inclusion of transverse shear deformation in finite element displacement formulations (1974)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-16
    Beschreibung: A stiffness matrix is derived for a beam element with transverse shear deformation. It is shown that straightforward energy minimization yields the correct stiffness matrix in displacement formulations when transverse shear effects are considered. Since the TIM4 beam element does not represent the geometric boundary conditions for a cantilever beam the rotation of the normal must be retained as a grid point degree of freedom.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: AIAA Journal; 12; Nov. 197
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  • 28
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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
    Details
    Publikationsdatum: 2011-08-16
    Beschreibung: 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.
    Schlagwort(e): SPACE RADIATION
    Materialart: Astrophysical Journal; 192; Sept. 15
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  • 29
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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
    Publikationsdatum: 2011-08-16
    Beschreibung: 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.
    Schlagwort(e): SPACE RADIATION
    Materialart: ESRO The Context and Status of Gamma Ray Astronomy; p 241-248
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    Observations of discrete gamma ray sources with SAS-2 (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: 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.
    Schlagwort(e): SPACE RADIATION
    Materialart: ESRO The Context and Status of Gamma Ray Astronomy; p 273-277
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  • 31
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    New diagnostic technique for the study of turbulent boundary-layer separation (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: Description of a diagnostic technique for determining the unsteady character of turbulent boundary-layer separation. The technique uses thin platinum films mounted flush with the model surface. Voltages from these films provide measurements related to the flow character above the film. For illustration, results obtained by this technique are presented for the interaction of a hypersonic shock wave and a turbulent boundary layer, with and without separation.
    Schlagwort(e): FLUID MECHANICS
    Materialart: AIAA Journal; 12; Oct. 197
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  • 32
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    Optical antenna gain. II - Receiving antennas (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: Expressions are developed for the gain of a centrally obscured, circular optical antenna used as the collecting and focusing optics in a laser receiver, involving losses due to (1) incoming light blockage by central obscuration, (2) energy spillover at the detector, and (3) the effect of local oscillator distribution in the case of heterodyne or homodyne detection. Numerical results are presented for direct detection and for three types of local oscillator distribution (uniform, Gaussian, and matched).
    Schlagwort(e): COMMUNICATIONS
    Materialart: Applied Optics; 13; Oct. 197
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  • 33
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    Cosmic electrons (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: 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.
    Schlagwort(e): SPACE RADIATION
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  • 34
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    Solar particles /observations, relationship to the sun acceleration, interplanetary medium/ (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: 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.
    Schlagwort(e): SPACE RADIATION
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  • 35
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    Reynolds-shear-stress measurements in a compressible boundary layer within a shock-wave-induced adverse pressure gradient (1974)
    In:  Other Sources
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    Publikationsdatum: 2011-08-16
    Schlagwort(e): FLUID MECHANICS
    Materialart: Journal of Fluid Mechanics; 65; Aug. 12
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  • 36
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    Optical antenna gain. I - Transmitting antennas (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: The gain of centrally obscured optical transmitting antennas is analyzed in detail. The calculations, resulting in near- and far-field antenna gain patterns, assume a circular antenna illuminated by a laser operating in the TEM-00 mode. A simple polynomial equation is derived for matching the incident source distribution to a general antenna configuration for maximum on-axis gain. An interpretation of the resultant gain curves allows a number of auxiliary design curves to be drawn that display the losses in antenna gain due to pointing errors and the cone angle of the beam in the far field as a function of antenna aperture size and its central obscuration. The results are presented in a series of graphs that allow the rapid and accurate evaluation of the antenna gain which may then be substituted into the conventional range equation.
    Schlagwort(e): COMMUNICATIONS
    Materialart: Applied Optics; 13; Sept
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  • 37
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    Alterations in left ventricular volumes induced by Valsalva manoeuvre (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: Five patients were studied with left ventriculography during different phases of the Valsalva manoeuvre. Small doses of contrast medium allowed adequate repetitive visualization of the left ventricle for volume calculation. During strain phase, the volume of the left ventricle decreased by nearly 50 per cent in each case, and stroke volume and cardiac output also dropped strikingly. Release of straining was attended by a sharp rebound of left ventricular volume to control levels, with a transient surge of increased cardiac output 42 per cent above that of the resting state.
    Schlagwort(e): BIOSCIENCES
    Materialart: British Heart Journal; 36; July 197
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  • 38
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    Evolution of a moderately short turbulent boundary layer in a severe pressure gradient (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: The early and intermediate development of a highly accelerated (or decelerated) turbulent boundary layer is analyzed. For sufficiently large accelerations (or pressure gradients) and for total normal strains which are not excessive, the equation for the Reynolds shear stress simplifies to give a stress that remains approximately constant as it is convected along streamlines. The theoretical results for the evolution of the mean velocity in favourable and adverse pressure gradients agree well with experiment for the cases considered. A calculation which includes mass injection at the wall is also given.
    Schlagwort(e): FLUID MECHANICS
    Materialart: Journal of Fluid Mechanics; 64; July 24
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  • 39
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    Microcraters formed in glass by projectiles of various densities (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: An experiment was conducted investigating the effect of projectile density on the structure and size of craters in soda lime glass and fused quartz. The projectiles were spheres of polystyrene-divinylbenzene (PS-DVB), aluminum, and iron with velocities between 0.5 and 15 km/sec and diameters between 0.4 and 5 microns. The projectile densities spanned the range expected for primary and secondary particles of micrometer size at the lunar surface, and the velocities spanned the lower range of micrometeoroid velocities and the upper range of secondary projectile velocities. There are changes in crater morphology as the impact velocity increases, and the transitions occur at lower velocities for the projectiles of higher density. The sequence of morphological features of the craters found for PS-DVB impacting soda lime glass for increasing impact velocity, described in a previous work (Mandeville and Vedder, 1971), also occurs in fused quartz and in both targets with the more dense aluminum and iron projectiles. Each transition in morphology occurs at impact velocities generating a certain pressure in the target. High density projectiles require a lower velocity than low-density projectiles to generate a given shock pressure.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: Journal of Geophysical Research; 79; Aug. 10
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  • 40
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    Apollo space crew cardiovascular evaluations (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: Cardiovascular responses associated with pre- and postflight orthostatic tolerance evaluations of Apollo crewmen are presented with a brief historical survey and a discussion of their implications for future manned space flight. Heart rates were increased while systolic and pulse pressures were decreased during the immediate postflight orthostatic evaluation. A postflight elevation in resting heart rate was a less frequent finding.
    Schlagwort(e): BIOSCIENCES
    Materialart: Aerospace Medicine; 45; Aug. 197
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    Recovery of medically important microorganisms from Apollo astronauts (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: Microbiological samples were obtained from the crewmembers of the Apollo 13, 14, 15, 16, and 17 spaceflights. These specimens were analyzed for the presence of medically important microorganisms with Staphylococcus aureus, Pseudomonas aeruginosa, Tricophyton mentagrophytes, Tricophyton rubrum, and Candida albicans being discussed in detail. Preflight isolation of crewmembers was found to coincide with a complete absence of inflight disease events and is recommended for future spaceflights. No autoinfection response (microbial shock) occurred after any of the reported spaceflights.
    Schlagwort(e): BIOSCIENCES
    Materialart: Aerospace Medicine; 45; Aug. 197
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  • 42
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    Sweet's mechanism in the solar wind (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: 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.
    Schlagwort(e): SPACE RADIATION
    Materialart: Astrophysical Journal; 191; Aug. 1
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  • 43
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    Approximate techniques of structural reanalysis (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: A study is made of two approximate techniques for structural reanalysis. These include Taylor series expansions for response variables in terms of design variables and the reduced-basis method. In addition, modifications to these techniques are proposed to overcome some of their major drawbacks. The modifications include a rational approach to the selection of the reduced-basis vectors and the use of Taylor series approximation in an iterative process. For the reduced basis a normalized set of vectors is chosen which consists of the original analyzed design and the first-order sensitivity analysis vectors. The use of the Taylor series approximation as a first (initial) estimate in an iterative process, can lead to significant improvements in accuracy, even with one iteration cycle. Therefore, the range of applicability of the reanalysis technique can be extended. Numerical examples are presented which demonstrate the gain in accuracy obtained by using the proposed modification techniques, for a wide range of variations in the design variables.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: Computers and Structures; 4; Aug. 197
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  • 44
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    Alteration of pituitary-adrenal dynamics induced by a water deprivation regimen (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: Experiments are described which were designed to assess the degree of adaptation that occurs in rats chronically exposed to the stress of a water-deprivation regimen and to determine if that adaptation represents a normalization of the hypothalamic-pituitary-adrenal axis. There were no significant differences in mean corticosterone concentrations among control nondeprived rats 1, 4, and 8 weeks after the start of the experiment. The water-deprived rats, however, had significantly elevated plasma steroids 1 and 4 weeks after the onset of deprivation as compared to controls, but not after 8 weeks. Thus, there was a significant decrease in mean plasma corticosterone levels during water deprivation from 1 week to 8 weeks.
    Schlagwort(e): BIOSCIENCES
    Materialart: Physiology and Behavior; 12; 1974
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  • 45
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    The subsequence weight distribution of summed maximum length digital sequences (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: An attempt is made to develop mathematical formulas to provide the basis for the design of pseudorandom signals intended for applications requiring accurate knowledge of the statistics of the signals. The analysis approach involves calculating the first five central moments of the weight distribution of subsequences of hybrid-sum sequences. The hybrid-sum sequence is formed from the modulo-two sum of k maximum length sequences and is an extension of the sum sequences formed from two maximum length sequences that Gilson (1966) evaluated. The weight distribution of the subsequences serves as an approximation to the filtering process. The basic reason for the analysis of hybrid-sum sequences is to establish a large group of sequences with good statistical properties. It is shown that this can be accomplished much more efficiently using the hybrid-sum approach rather than forming the group strictly from maximum length sequences.
    Schlagwort(e): COMMUNICATIONS
    Materialart: IEEE Transactions on Communications; COM-22; Aug. 197
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  • 46
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    Turbulent diffusion with memories and intrinsic shear (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: The first part of the present theory is devoted to the derivation of a Fokker-Planck equation. The eddies smaller than the hydrodynamic scale of the diffusion cloud form a diffusivity, while the inhomogeneous, bigger eddies give rise to a nonuniform migratory drift. This introduces an eddy-induced shear which reflects on the large-scale diffusion. The eddy-induced shear does not require the presence of a permanent wind shear and is intrinsic to the diffusion. Secondly, a transport theory of diffusivity is developed by the method of repeated-cascade and is based upon a relaxation of a chain of memories with decreasing information. The full range of diffusion consists of inertia, composite, and shear subranges, for which variance and eddy diffusivities are predicted. The coefficients are evaluated. Comparison with experiments in the upper atmosphere and oceans is made.
    Schlagwort(e): FLUID MECHANICS
    Materialart: Zeitschrift fuer Naturforschung; vol. 29a
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    The distribution of cosmic rays in the Galaxy and their dynamics as deduced from recent gamma-ray observations (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: 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.
    Schlagwort(e): SPACE RADIATION
    Materialart: Astrophysical Journal; 191; July 15
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  • 48
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    Origin of QSO absorption lines (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: 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.
    Schlagwort(e): SPACE RADIATION
    Materialart: Nature; 250; July 26
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  • 49
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    478-keV and 431-keV line emissions from alpha-alpha reactions (1974)
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    Publikationsdatum: 2011-08-16
    Schlagwort(e): SPACE RADIATION
    Materialart: Astrophysical Journal; 191; July 1
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  • 50
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    1.0 arc second structure on the sun at 3.71 cm wavelength (1974)
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    Publikationsdatum: 2011-08-16
    Schlagwort(e): SPACE RADIATION
    Materialart: Solar Physics; 36; June 197
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    Ionization equilibrium in soft X-ray-emitting solar flares (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: 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.
    Schlagwort(e): SPACE RADIATION
    Materialart: Solar Physics; 36; June 197
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    Solar longitude dependence of some characteristics of type III radio bursts from metric to hectometric wavelengths (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: 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.
    Schlagwort(e): SPACE RADIATION
    Materialart: Solar Physics; 36; May 1974
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    On helium-like 1s2l-1snl prime transitions in solar flare spectra (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: 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.
    Schlagwort(e): SPACE RADIATION
    Materialart: Solar Physics; 36; May 1974
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  • 54
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    On numerical methods to impose asymptotic boundary conditions of boundary-layer equations (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: The error minimization method proposed by Nachtsheim and Swigert (1965) to satisfy the asymptotic boundary conditions of boundary layer equations is proved to be equivalent to imposing the condition of fastest decay. As a consequence, a uniqueness problem is not arising in the solutions of boundary layer equations obtained by their method.
    Schlagwort(e): FLUID MECHANICS
    Materialart: Computers and Fluids; 2; Mar. 197
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  • 55
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    Method for producing a uniform, low Reynolds number jet (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: In one attempt to produce a simple inexpensive nozzle, a 2-in. diam plate with 37 holes was investigated (Stadler, 1960), anticipating that the small jets emanating from the plate would combine to form a uniform stream. This experiment was unsuccessful because a uniform flow was not established until the flow had progressed many nozzle diameters downstream. However, an extension of this concept to a much larger number of very small jets, viz., a porous plate, did provide a method for producing a uniform, low Reynolds number jet almost immediately downstream of the nozzle (Greene, 1973). The method is described and some typical jet velocity profiles for nozzle Reynolds numbers from 50 to 1000 are given.
    Schlagwort(e): FLUID MECHANICS
    Materialart: Journal of Spacecraft and Rockets; 11; Aug. 197
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  • 56
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    Effects of simulated weightlessness on responses of untrained men to +Gz acceleration (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: This study documents bedrest-induced metabolic and physiologic changes in six untrained men exposed, following a two-week period of simulated weightlessness, to possible +Gz acceleration profiles anticipated for Space Shuttle vehicle travel. All subjects demonstrated decreased +Gz tolerance following simulated weightlessness. While only one of six subjects could not tolerate the +Gz profile in the control phase of the study, three of the six could not complete the postbed-rest study. The use of an inflated standard Air Force cutaway G-suit improved +Gz tolerance in all subjects, but two of six subjects still failed to complete the profile. These findings are discussed in reference to the selection of untrained humans for Space Shuttle vehicle travel.
    Schlagwort(e): BIOSCIENCES
    Materialart: Journal of Applied Physiology; 36; June 197
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    The Fokker-Planck coefficient for pitch-angle scattering of cosmic rays (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: 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.
    Schlagwort(e): SPACE RADIATION
    Materialart: Astrophysical Journal; 190; June 1
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  • 58
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    Empirical solar proton model for orbiting spacecraft applications (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: 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.
    Schlagwort(e): SPACE RADIATION
    Materialart: IEEE Transactions on Aerospace and Electronic Systems; AES-10; July 197
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    Solar proton fluences for 1977-1983 space missions (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: 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.
    Schlagwort(e): SPACE RADIATION
    Materialart: Journal of Spacecraft and Rockets; 11; June 197
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    The anomalous abundance of cosmic-ray nitrogen and oxygen nuclei at low energies (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: 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.
    Schlagwort(e): SPACE RADIATION
    Materialart: Astrophysical Journal; 187; Feb. 1
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  • 61
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    Approach to the origin of turbulence on the basis of two-point kinetic theory (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: Equations for the fluctuation correlation in an incompressible shear flow are derived on the basis of kinetic theory, utilizing the two-point distribution function which obeys the BBGKY hierarchy equation truncated with the hypothesis of 'ternary' molecular chaos. The step from the molecular to the hydrodynamic description is accomplished by a moment expansion which is a two-point version of the thirteen-moment method, and which leads to a series of correlation equations, viz., the two-point counterparts of the continuity equation, the Navier-Stokes equation, etc. For almost parallel shearing flows the two-point equation is separable and reduces to two Orr-Sommerfeld equations with different physical implications.
    Schlagwort(e): FLUID MECHANICS
    Materialart: Physics of Fluids; 17; Jan. 197
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    Static, stability, and dynamic analysis of shells of revolution by numerical integration - A comparison (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: Recent innovations in digital computer technology have enabled engineers to analyze shell structures of complex configurations without unduly restrictive approximations. An attempt is made to compare the various programs now generally available from the point of view of the advantages of the relative technique utilized, as well as the programmed state of the art. Many of the comparisons are based on the sample problems solved by the STARS-2 system of programs. These examples indicate both the structural detail which can be analyzed by, and the analytical capabilities available in, the numerical shell-of-revolution programs. All advantages and differences are demonstrated by use of solutions for realistic shell problems in the areas of statics, stability, vibrations, and dynamic response of shells subjected to time-dependent loadings.
    Schlagwort(e): STRUCTURAL MECHANICS
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    Computer simulation of the Pioneer 10 microwave occultation experiment (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: As Pioneer 10 approaches the planet Jupiter, its trajectory will carry it behind the planet, as seen from the earth. The microwave telemetry signal from the spacecraft will then pass through the Jovian atmosphere on its way to the earth, and analysis of the effects of the atmosphere on the signal should yield information on the atmospheric structure. To help define the capabilities of this experiment and to aid the analysis of the real data, we have simulated the occultation experiment on a computer by using model Jovian atmospheres and a predicted trajectory. The results indicate that the useful depth of penetration of the microwave signal will be governed by ammonia absorption rather than superrefractivity. The experiment is apparently far more sensitive to variations in cloud-top temperature than to variations in the hydrogen-helium ratio. Characteristic 'flashes' in the attenuation record of the signal may yield information on the location of the top of the Jovian convective zone.
    Schlagwort(e): COMMUNICATIONS
    Materialart: Journal of Geophysical Research; 79; May 1
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    Mutual coupling in a finite planar array of circular apertures (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: Equations are presented for the calculation of the interelement mutual coupling in a finite-size planar array of waveguide-fed apertures in an infinite flat conductor. The general mutual admittance expression is evaluated for circular apertures, and the mutual coupling calculations are verified experimentally for two Te-(11) mode excited apertures. Qualitative agreement between calculations for a 183-element array and an infinite array establishes the validity of the finite-array theoretical model.
    Schlagwort(e): COMMUNICATIONS
    Materialart: IEEE Transactions on Antennas and Propagation; AP-22; Mar. 197
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  • 65
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    Channel simulation for optical communication systems (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: A technique is reported for simulating the signal fading that will be experienced by typical optical communication systems. The desired irradiance or amplitude fading statistics can be simulated by incorporating a linearized optical modulator subsystem between the transmitter and receiver. This technique has been implemented in the design and construction of a laboratory channel simulator. The design of the processing electronics is discussed along with the results of tests performed for each mode of operation.
    Schlagwort(e): COMMUNICATIONS
    Materialart: Applied Optics; 13; June 197
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  • 66
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    Forced vibrations of multi-component compliant tanks and feedlines (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: An analytical and experimental research program was performed to investigate the effects of flexible tanks and lines and the total system dynamic response of a simple physical system which had some of the essential features of a liquid-fueled launch vehicle. Several vessel-wall materials were used to obtain a range of elastic moduli. Water was used to simulate the fuel and an electromagnetic shaker provided external excitation such as might originate from a rocket-propulsion system. Experimental data were compared to values obtained from mathematical models for the many degree-of-freedom lumped-mass representation.
    Schlagwort(e): STRUCTURAL MECHANICS
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  • 67
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    An upper limit on soft X-ray pulsations from the pulsar PSR 0833-45 (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: 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.
    Schlagwort(e): SPACE RADIATION
    Materialart: Astrophysical Journal; 189; May 1
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  • 68
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    On first cycle slip time of phase-locked loops in cascade (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: Precise measurement and spacecraft tracking are obtained by using phase-locked loops in cascade in two-way communications links. Statistics on cycle slip time are of vital importance in system planning and design. This paper presents: (1) results of a computer simulation study of the mean time to first cycle slip of cascade phase-locked loops preceded by bandpass limiters, and (2) the determination of probability distributions of cycle slip. Numerical results are obtained for a typical coherent communication system.
    Schlagwort(e): COMMUNICATIONS
    Materialart: IEEE Transactions on Aerospace and Electronic Systems; AES-10; May 1974
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  • 69
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    Computation of steady nozzle flow by a time-dependent method (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: The equations of motion governing steady, inviscid flow are of a mixed type, that is, hyperbolic in the supersonic region and elliptic in the subsonic region. These mathematical difficulties may be removed by using the so-called time-dependent method, where the governing equations become hyperbolic everywhere. The steady-state solution may be obtained as the asymptotic solution for large time. The object of this research was to develop a production type computer program capable of solving converging, converging-diverging, and plug two-dimensional nozzle flows in computational times of 1 min or less on a CDC 6600 computer.
    Schlagwort(e): FLUID MECHANICS
    Materialart: AIAA Journal; 12; Apr. 197
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  • 70
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    Nonproportional loading limit for structures (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: The design of most structures involves ensuring integrity for several independent loading conditions. Often, it is rational to design these, exploiting the ductility of the materials to reduce structural costs. Then, ensuring integrity evokes the need for nonmonotonic limit analyses. A groundwork is laid for implementing these analyses. An alternate limit load characterization to that of Greenberg is provided, a mathematical statement of the problem leading to both monotonic (proportional) and nonmonotonic limit loads values is formulated, a direct limit load analysis procedure for analysis within a finite-element framework is described, and limit loads for sets of simple structures are evaluated. A direct limit analysis process is described, and monotonic limit loads are characterized. The process furnishes 'exact' values of limit loads with increasing efficiency as the number of structural elements and force redundancy decreases. Tests show that the accuracy of predicting nonmonotonic limit loads is very sensitive to the number of degrees of freedom in the analysis compared with the total number in the model.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: Computers and Structures; 4; Mar. 197
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  • 71
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    The helium component of solar wind velocity streams (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: 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.
    Schlagwort(e): SPACE RADIATION
    Materialart: Journal of Geophysical Research; 79; Mar. 1
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  • 72
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    Bistatic scatter from rain (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: An experimental investigation of bistatic scatter from rain was conducted, using a 143-km scatter path at frequencies of 4.5 and 7.7 GHz. The ratio of transmitted to received power (transmission loss) was measured for scattering angles ranging from 6 to 130 deg. Simultaneous weather radar observations were made at a frequency of 1.3 GHz. Transmission loss estimates for the bistatic scatter path were computed, using the weather radar data, the bistatic radar equation, and a model for the scattering cross section per unit volume of rain based upon Rayleigh scattering by an ensemble of water spheres. The measured and estimated transmission loss values were compared to test the use of the scattering model for the estimation of interference. The averaged ratio of measured-to-calculated transmission loss for the 4.5 GHz data is 1.2 plus or minus 0.4 dB. The averaged ratio for the 7.7 GHz data is -1.6 plus or minus 0.5 dB.
    Schlagwort(e): COMMUNICATIONS
    Materialart: IEEE Transactions on Antennas and Propagation; AP-22; Mar. 197
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    Determination of left ventricular size and shape (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: Significant advances have occurred over the past 15 years in the ability to measure ventricular dimensions. Angiocardiography still remains the most reliable method for overall determination of chamber size and shape and serves as a standard for calibration or comparison for newer methods. Improvements in the use of radiographic methods over the next few years are anticipated with more extensive use of multiplane studies associated with repeated injections of improved contrast materials that produce fewer physiological effects or with substances that adhere to the endocardial surfaces. It is also anticipated that existing methods for automatically obtaining dimensional information from X rays will be continued and improved.
    Schlagwort(e): BIOSCIENCES
    Materialart: Circulation Research; 34; Jan. 197
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  • 74
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    Effects of heavy ions on electron temperatures in the solar corona and solar wind (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: 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.
    Schlagwort(e): SPACE RADIATION
    Materialart: Journal of Geophysical Research; 79; Jan. 1
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    Some effects of diffusion on the flow of ions in the solar wind (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: 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++.
    Schlagwort(e): SPACE RADIATION
    Materialart: Journal of Geophysical Research; 79; Apr. 1
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  • 76
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    Flow properties in expansion tube with helium, argon, air, and CO2 (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: Test flow velocities from 5 to 7 km/sec were generated in a 6-in. expansion tube using helium, argon, air, and CO2 test gases. Pitot pressure profiles across the flow at the test section are presented for the four test gases, and measured flow quantities are compared to computer predicted values. Comparison of predicted and measured flow quantities suggests the expansion to be near thermochemical equilibrium for all test gases and implies the existence of a totally reflected shock at the secondary diaphragm. Argon, air, and CO2 flows were observed to attenuate while traversing the acceleration section, whereas no attenuation was observed for helium.
    Schlagwort(e): FLUID MECHANICS
    Materialart: AIAA Journal; 12; Apr. 197
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    Serotonin and pituitary-adrenal function (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: An investigation is conducted to evaluate the response of the pituitary-adrenal system to a stress stimulus in the rat. In the investigation brain serotonin synthesis was inhibited with p-chlorophenylalanine. In other tests the concentration of serotonin was enhanced with precursors such as tryptophan or 5-hydroxytryptophan. On the basis of the results obtained in the study it is speculated that in some disease states there is a defect in serotonergic neuronal processes which impairs pituitary-adrenal feedback mechanisms.
    Schlagwort(e): BIOSCIENCES
    Materialart: Nature; 248; Mar. 29
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    Adhesive fracture mechanics (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: In studies of fracture mechanics the adhesive fracture energy is regarded as a fundamental property of the adhesive system. It is pointed out that the value of the adhesive fracture energy depends on surface preparation, curing conditions, and absorbed monolayers. A test method reported makes use of a disk whose peripheral part is bonded to a substrate material. Pressure is injected into the unbonded central part of the disk. At a certain critical pressure value adhesive failure can be observed. A numerical stress analysis involving arbitrary geometries is conducted.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: International Journal of Fracture; 10; Mar. 197
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    Life span and fine structural changes in oxygen-poisoned drosophila melanogaster (1974)
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    Publikationsdatum: 2011-08-16
    Schlagwort(e): BIOSCIENCES
    Materialart: Aerospace Medicine; 45; Mar. 197
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  • 80
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    Non-equilibrium ionized blast wave (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: The structure of a cylindrical blast wave with ionization at non-LTE conditions was calculated using equations previously developed by Wu and Fu (1970). The degree of ionization was predicted by a modified Saha equation. Temperature profiles show that the temperature at non-LTE conditions is lower than at LTE near the shock front. This corresponds to a higher degree of ionization for the non-LTE limit, which indicates that the neutral gas absorption is much more efficient at non-LTE than at the LTE limit. The decaying velocity under non-LTE is approximately 15% less than under LTE.
    Schlagwort(e): FLUID MECHANICS
    Materialart: Physical Society of Japan; vol. 36
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    Some measurements of the attenuation of solar radiation during BOMEX (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: 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.
    Schlagwort(e): SPACE RADIATION
    Materialart: Applied Optics; 13; Mar. 197
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    Cosmic far ultraviolet background (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: 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.
    Schlagwort(e): SPACE RADIATION
    Materialart: Nature; 247; Feb. 22
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    Coherent scattering of cosmic neutrinos (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: 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.
    Schlagwort(e): SPACE RADIATION
    Materialart: Astronomy and Astrophysics; 37; 1, De; Dec. 197
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    New triangular plate-bending finite element with transverse shear flexibility (1974)
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    Publikationsdatum: 2011-08-16
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: AIAA Journal; 12; Dec. 197
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    Search for optical emission from cosmic gamma-ray bursts (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: 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.
    Schlagwort(e): SPACE RADIATION
    Materialart: Astrophysical Journal; 192; Sept. 15
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    The origin of the diffuse background gamma radiation (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: 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.
    Schlagwort(e): SPACE RADIATION
    Materialart: 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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    Publikationsdatum: 2011-08-16
    Beschreibung: 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.
    Schlagwort(e): SPACE RADIATION
    Materialart: ESRO The Context and Status of Gamma Ray Astronomy; p 37-45
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    Gamma radiation from the Crab Nebula above 35 MeV (1974)
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    Publikationsdatum: 2011-08-16
    Schlagwort(e): SPACE RADIATION
    Materialart: Nature; 251; Oct. 4
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    Cosmic rays - Astronomy with energetic particles (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: 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.
    Schlagwort(e): SPACE RADIATION
    Materialart: Physics Today; 27; Oct. 197
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  • 90
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    Irregular bilayer structure in vesicles prepared from Halobacterium cutirubrum lipids (1974)
    In:  Other Sources
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    Publikationsdatum: 2011-08-16
    Beschreibung: Fluorescent probes were used to study the structure of the cell envelope of Halobacterium cutirubrum, and, in particular, to explore the effect of the heterogeneity of the lipids in this organism on the structure of the bilayers. The fluorescence polarization of perylene was followed in vesicles of unfractionated lipids and polar lipids as a function of temperature in 3.4 M solutions of NaCl, NaNO3, and KSCN, and it was found that vesicles of unfractionated lipids were more perturbed by chaotropic agents than polar lipids. The dependence of the relaxation times of perylene on temperature was studied in cell envelopes and in vesicles prepared from polar lipids, unfractionated lipids, and mixtures of polar and neutral lipids.
    Schlagwort(e): BIOSCIENCES
    Materialart: Biochimica et Biophysica Acta; 356; 1974
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  • 91
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    Integrated laser/radar satellite ranging and tracking system (1974)
    In:  Other Sources
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    Publikationsdatum: 2011-08-16
    Beschreibung: A laser satellite ranging system that is mounted upon and integrated with a microwave tracking radar is reported. The 1-pulse/sec ruby laser transmitter is attached directly to the radar's elevation axis and radiates through a new opening in the radar's parabolic dish. The laser photomultiplier tube receiver utilizes the radar's existing 20-cm diam f/11 boresight telescope and observes through a similar symmetrically located opening in the dish. The laser system possesses separate ranging system electronics but shares the radar's timing, computer, and data handling/recording systems. The basic concept of the laser/radar is outlined together with a listing of the numerous advantages over present singular laser range-finding systems. The developmental laser hardware is described along with preliminary range-finding results and expectations.
    Schlagwort(e): COMMUNICATIONS
    Materialart: Applied Optics; 13; Oct. 197
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    Standort Signatur Erwartet Verfügbarkeit
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  • 92
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    The abundances of nuclei in the cosmic radiation (1974)
    In:  Other Sources
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    Publikationsdatum: 2011-08-16
    Beschreibung: 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.
    Schlagwort(e): SPACE RADIATION
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  • 93
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    High energy particles and quanta in astrophysics (1974)
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    Publikationsdatum: 2016-03-07
    Beschreibung: 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.
    Schlagwort(e): SPACE RADIATION
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  • 94
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    Cosmic ray experimental observations (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: 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.
    Schlagwort(e): SPACE RADIATION
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  • 95
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    Human radiation tolerance (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: The acute radiation syndrome in man is clinically bounded by death at high dose levels and by the prodromal syndrome of untoward physiological effects at minimal levels of clinically effective exposure. As in lower animals, man experiences principally three acute modes of death from radiation exposure (Bond et al., 1965). These are known collectively as the lethal radiation syndromes: central nervous system death, gastrointestinal death, and hematopoietic death. The effect of multiple exposure on lethality, the effect of multiple exposure on hematopoietic recovery, and quantitative aspects of cell and tissue repair are discussed.
    Schlagwort(e): BIOSCIENCES
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  • 96
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    Ultrastructural response of rat lung to 90 days' exposure to oxygen at 450 mm Hg (1974)
    In:  Other Sources
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    Publikationsdatum: 2011-08-16
    Beschreibung: Young Sprague-Dawley rats were exposed to 100% oxygen at 450 mm Hg in constant environment capsules for 90 days. Lung tissue examined by electron microscopy revealed a number of changes, many similar to those observed after exposure to oxygen at 760 mm Hg for shorter periods of time. Alterations in vesicle size and number and in mitochondrial matrix and cristae appear in both the endothelial and epithelial cells. Blebbing and rarefication of cytoplasm occur in both cell layers of the alveolo-capillary wall. Also seen are fluid in the basement membrane, platelets in the capillaries, and alveolar fluid and debris. All of these alterations occur at 1 atm exposure. However, after exposure to 450 mm Hg the changes are not as widespread nor as destructive as they are at the higher pressure.
    Schlagwort(e): BIOSCIENCES
    Materialart: Aerospace Medicine; 45; Sept
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  • 97
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    Remarks on the decay of homogeneous turbulence from a given state (1974)
    In:  Other Sources
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    Publikationsdatum: 2011-08-16
    Beschreibung: A previous theory which did not require a usual closure assumption required three or more initial spectra. By allowing a simple physical assumption (a modification of Kovasznay's (1948) hypothesis), the required number of spectra is reduced to two. Agreement with experiment is good.
    Schlagwort(e): FLUID MECHANICS
    Materialart: Physics of Fluids; 17; Mar. 197
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  • 98
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    A discussion of interplanetary postshock flows with two examples (1974)
    In:  Other Sources
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    Publikationsdatum: 2011-08-16
    Beschreibung: 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.
    Schlagwort(e): SPACE RADIATION
    Materialart: Journal of Geophysical Research; 79; June 1
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  • 99
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    Interactive design of large end rings on stiffened conical shells using composites (1974)
    In:  Other Sources
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    Publikationsdatum: 2011-08-16
    Beschreibung: Design study methods and results for a composite reinforced base ring for the conical aeroshell structure of the planetary lander vehicle for Project Viking, an unmanned mission to Mars, are presented. The aeroshell is a ring and stringer-stiffened conical shell structure having a half angle of 70 degrees with a large base ring mounted at the outer edge of the cone and a large pay-load ring in the interior with many smaller rings spaced along the inside shell surface. The purpose of the structure is to develop the aerodynamic drag required to decelerate the lander in the Mars atmosphere to facilitiate a soft landing. The design of a shell structure of this complexity requires the use of the latest technology available in a large general-purpose shell buckling program. The large general-purpose non-linear shell buckling program (BOSOR 2) which was used for this purpose is described.
    Schlagwort(e): STRUCTURAL MECHANICS
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  • 100
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    Possible evidence for structured acceleration of cosmic rays on a galactic scale from recent gamma-ray observations (1974)
    In:  Other Sources
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    Publikationsdatum: 2011-08-16
    Beschreibung: 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.
    Schlagwort(e): SPACE RADIATION
    Materialart: Astrophysical Journal; 188; Mar. 1
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