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  • General Chemistry  (7,564)
  • STRUCTURAL MECHANICS  (1,510)
  • PROPULSION SYSTEMS  (1,456)
  • COMMUNICATIONS  (1,377)
  • Cell & Developmental Biology
  • 1970-1974  (10,043)
  • 1910-1914  (2,932)
Collection
Keywords
Publisher
Years
Year
  • 1
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    Radio communications with extra-terrestrial civilizations (1974)
    In:  CASI
    Details
    Publication Date: 2006-01-11
    Description: 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.
    Keywords: COMMUNICATIONS
    Type: Inhabited Space, Pt. 2 (NASA-TT-F-820); p 79-82
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  • 2
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    Noise and vibration level reduction by covering metal structures with layers of damping materials (1974)
    In:  CASI
    Details
    Publication Date: 2006-01-11
    Description: 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.
    Keywords: STRUCTURAL MECHANICS
    Type: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 246-253
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  • 3
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    Reduction of diesel engine exhaust noise in the petroleum mining industry (1974)
    In:  CASI
    Details
    Publication Date: 2006-01-11
    Description: An important noise source in a drilling plant is Diesel engine exhaust. In order to reduce this noise, a reactive silencer of the derivative resonator type was proposed, calculated from the acoustic and design point of view and applied. As a result of applying such a silencer on the exhaust conduit of a Diesel engine the noise level dropped down to 18 db.
    Keywords: PROPULSION SYSTEMS
    Type: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 156-162
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  • 4
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    Vibration and recoil control of pneumatic hammers (1974)
    In:  CASI
    Details
    Publication Date: 2006-01-11
    Description: 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.
    Keywords: STRUCTURAL MECHANICS
    Type: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 79-84
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  • 5
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    Vibration control in forge hammers (1974)
    In:  CASI
    Details
    Publication Date: 2006-01-11
    Description: 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.
    Keywords: STRUCTURAL MECHANICS
    Type: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 73-78
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  • 6
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    Experimental determination of the vibration level in 5,100 kW electric locomotive assemblies (1974)
    In:  CASI
    Details
    Publication Date: 2006-01-11
    Description: 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.
    Keywords: STRUCTURAL MECHANICS
    Type: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 50-54
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  • 7
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    Random vibrations of linear viscoelastic beams with lumped masses (1974)
    In:  CASI
    Details
    Publication Date: 2006-01-11
    Description: 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.
    Keywords: STRUCTURAL MECHANICS
    Type: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 36-42
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  • 8
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    Random vibrations of quadratic damping systems (1974)
    In:  CASI
    Details
    Publication Date: 2006-01-11
    Description: 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.
    Keywords: STRUCTURAL MECHANICS
    Type: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 29-35
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  • 9
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    The response of many-storied structures under seismic actions (1974)
    In:  CASI
    Details
    Publication Date: 2006-01-11
    Description: 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.
    Keywords: STRUCTURAL MECHANICS
    Type: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 43-49
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  • 10
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    Insulation of nonlinear and random vibrations in the mining industry (1974)
    In:  CASI
    Details
    Publication Date: 2006-01-11
    Description: 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.
    Keywords: STRUCTURAL MECHANICS
    Type: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 22-28
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  • 11
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    A mathematical model for storied buildings subjected to automatic loom stresses (1974)
    In:  CASI
    Details
    Publication Date: 2006-01-11
    Description: 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.
    Keywords: STRUCTURAL MECHANICS
    Type: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 15-21
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  • 12
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    Study of vibrations produced by a vibrating beam used for vibrating concretes (1974)
    In:  CASI
    Details
    Publication Date: 2006-01-11
    Description: 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.
    Keywords: STRUCTURAL MECHANICS
    Type: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 9-14
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  • 13
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    Intermediate memory devices (1974)
    In:  CASI
    Details
    Publication Date: 2006-01-11
    Description: 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.
    Keywords: COMMUNICATIONS
    Type: Space Res. in the Ukraine, No. 3 (NASA-TT-F-15537); p 155-162
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  • 14
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    Electromagnetic processes in the atmosphere of pulsars (1974)
    In:  CASI
    Details
    Publication Date: 2006-01-11
    Description: 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.
    Keywords: COMMUNICATIONS
    Type: Space Res. in the Ukraine, No. 3, (NASA-TT-F-15537); p 44-53
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  • 15
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    The tropospheric calibration model for Mariner Mars 1971 (1974)
    In:  CASI
    Details
    Publication Date: 2006-01-11
    Description: 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.
    Keywords: COMMUNICATIONS
    Type: Tracking System Analytic Calibration Activities for the Mariner Mars 1971 Mission; p 61-76
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  • 16
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    Stresses in dome-shaped shells of revolution with discontinuities at the apex (1974)
    In:  CASI
    Details
    Publication Date: 2006-04-02
    Description: 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.
    Keywords: STRUCTURAL MECHANICS
    Type: Multivariant Function Model Generation; 118 p
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  • 17
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    Current structural vibration problems associated with noise (1974)
    In:  CASI
    Details
    Publication Date: 2011-10-14
    Description: 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.
    Keywords: STRUCTURAL MECHANICS
    Type: AGARD Noise Mech.; 16 p
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  • 18
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    Inclusion of transverse shear deformation in finite element displacement formulations (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: 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.
    Keywords: STRUCTURAL MECHANICS
    Type: AIAA Journal; 12; Nov. 197
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  • 19
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    Optical antenna gain. II - Receiving antennas (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: 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).
    Keywords: COMMUNICATIONS
    Type: Applied Optics; 13; Oct. 197
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  • 20
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    Optical antenna gain. I - Transmitting antennas (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: 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.
    Keywords: COMMUNICATIONS
    Type: Applied Optics; 13; Sept
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  • 21
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    Microcraters formed in glass by projectiles of various densities (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: 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.
    Keywords: STRUCTURAL MECHANICS
    Type: Journal of Geophysical Research; 79; Aug. 10
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  • 22
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    Electric propulsion - Now (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: The state of the art of electric propulsion technology is discussed with a review of the many difficult engineering problems which must be resolved before the incorporation of electric propulsion in space missions. Interferences with the spacecraft and its scientific instrumentation, conducted and radiated electromagnetic interferences during the switching and processing of large electrical loads, and mercury and other eroded materials deposition on the spacecraft are indicated among the engineering and design challenges to be overcome and resolved.
    Keywords: PROPULSION SYSTEMS
    Type: AIAA Student Journal; 12; Apr. 197
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  • 23
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    Approximate techniques of structural reanalysis (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: 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.
    Keywords: STRUCTURAL MECHANICS
    Type: Computers and Structures; 4; Aug. 197
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  • 24
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    The subsequence weight distribution of summed maximum length digital sequences (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: 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.
    Keywords: COMMUNICATIONS
    Type: IEEE Transactions on Communications; COM-22; Aug. 197
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  • 25
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    Quiet engine from NASA (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: Engine designs resulting from the NASA sponsored quiet engine program are described in terms of their possible use on the DC-8. These engines have high bypass ratios for low jet noise and low-speed, low-noise fans. Experiments were carried out on various fan designs with different tip speeds. The advantage of low tip speeds and high lift coefficients has been demonstrated. The engines are equipped with flight-standard nacelles with acoustic suppression. It is estimated that these improvements will reduce DC-8 noise by about 26EPNdB-29EPNdB.
    Keywords: PROPULSION SYSTEMS
    Type: Flight International; 106; July 25
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  • 26
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    Static, stability, and dynamic analysis of shells of revolution by numerical integration - A comparison (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: 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.
    Keywords: STRUCTURAL MECHANICS
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  • 27
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    Computer simulation of the Pioneer 10 microwave occultation experiment (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: 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.
    Keywords: COMMUNICATIONS
    Type: Journal of Geophysical Research; 79; May 1
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  • 28
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    Mutual coupling in a finite planar array of circular apertures (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: 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.
    Keywords: COMMUNICATIONS
    Type: IEEE Transactions on Antennas and Propagation; AP-22; Mar. 197
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  • 29
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    Channel simulation for optical communication systems (1974)
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    Publication Date: 2011-08-16
    Description: 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.
    Keywords: COMMUNICATIONS
    Type: Applied Optics; 13; June 197
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  • 30
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    Forced vibrations of multi-component compliant tanks and feedlines (1974)
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    Publication Date: 2011-08-16
    Description: 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.
    Keywords: STRUCTURAL MECHANICS
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  • 31
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    On first cycle slip time of phase-locked loops in cascade (1974)
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    Publication Date: 2011-08-16
    Description: 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.
    Keywords: COMMUNICATIONS
    Type: IEEE Transactions on Aerospace and Electronic Systems; AES-10; May 1974
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  • 32
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    Nonproportional loading limit for structures (1974)
    In:  Other Sources
    Details
    Publication Date: 2011-08-16
    Description: 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.
    Keywords: STRUCTURAL MECHANICS
    Type: Computers and Structures; 4; Mar. 197
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    Bistatic scatter from rain (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: 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.
    Keywords: COMMUNICATIONS
    Type: IEEE Transactions on Antennas and Propagation; AP-22; Mar. 197
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  • 34
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    Putting all our noise technology to work (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: An assessment of the present state of the art in noise reduction technology indicates that this technology has the potential for effectively attaining this goal - a conclusion that is in apparent conflict with the frequently voiced complaints on intolerable noise levels near airports. Measures are suggested for a more vigorous implementation of available technology in practice to combat the aircraft noise problem.
    Keywords: PROPULSION SYSTEMS
    Type: Astronautics and Aeronautics; 12; Jan. 197
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  • 35
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    Adhesive fracture mechanics (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: 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.
    Keywords: STRUCTURAL MECHANICS
    Type: International Journal of Fracture; 10; Mar. 197
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  • 36
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    New triangular plate-bending finite element with transverse shear flexibility (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Keywords: STRUCTURAL MECHANICS
    Type: AIAA Journal; 12; Dec. 197
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  • 37
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    Integrated laser/radar satellite ranging and tracking system (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: 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.
    Keywords: COMMUNICATIONS
    Type: Applied Optics; 13; Oct. 197
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  • 38
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    Interactive design of large end rings on stiffened conical shells using composites (1974)
    In:  Other Sources
    Details
    Publication Date: 2011-08-16
    Description: 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.
    Keywords: STRUCTURAL MECHANICS
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  • 39
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    Shortwave telemetric system (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: The application of frequency modulation when constructing a telemetric system in the shortwave band. The operating principles, the construction of the system and the decision making device are described and experimental data are presented. The equipment can be used on sounding balloons.
    Keywords: COMMUNICATIONS
    Type: Technol. for the Production of Space Equipment (NASA-TT-F-15766); p 59-65
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  • 40
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    Erosion and the gas turbine engine, part 2 (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: Procedures for protecting aircraft engines from impact damage due to sand and dust particles are discussed. One system is to develop a filtration system to remove most of the solid particles. Another method is to design blade materials and blade protection coatings. The concepts of erosion within aircraft engines are explained. Curves are presented to show the effect of impingement angle on ductile and elastic modes of erosion. Engine sand and dust ingestion tests were conducted on T63-A-5A engines and the results are produced in graph form. The results of tests conducted in a dynamic erosion facility are analyzed.
    Keywords: PROPULSION SYSTEMS
    Type: NBS The Role of Cavitation in Mech. Failures; p 129-145
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  • 41
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    Boundary value problems with incremental plasticity in granular media (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: Discussion of the critical state concept in terms of an incremental theory of plasticity in granular (soil) media, and formulation of the governing equations which are convenient for a computational scheme using the finite element method. It is shown that the critical state concept with its representation by the classical incremental theory of plasticity can provide a powerful means for solving a wide variety of boundary value problems in soil media.
    Keywords: STRUCTURAL MECHANICS
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  • 42
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    A solution to the contact of two rough spherical surfaces (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: The influence of roughness on the interfacial pressure distribution in the contact of two spherical surfaces is considered. An approximate general solution is presented and it is shown that the pressure for all radii can be determined solely from a reference pressure which is, in turn, a function of two parameters - a dimensionless roughness and a dimensionless hardness. Values for the radius of contact are also presented.
    Keywords: STRUCTURAL MECHANICS
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  • 43
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    Diffraction theory techniques applied to aperture antennas on finite circular and square ground planes (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: Expressions which represent the elevation-plane patterns of a large TEM mode coax aperture and a TM-01 mode circular aperture on finite circular and square ground planes have been derived using geometrical theory of diffraction; design curves for the coax case are presented. The expressions for the field pattern were obtained by superposing the infinite ground plane solutions, the first-order diffracted field solutions, and the axial caustic solutions in their respective regions of validity. The pattern analyses for the coax and circular apertures are verified experimentally.
    Keywords: COMMUNICATIONS
    Type: IEEE Transactions on Antennas and Propagation; AP-22; May 1974
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  • 44
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    Mixed mode stress field effect in adhesive fracture (1974)
    In:  Other Sources
    Details
    Publication Date: 2011-08-16
    Description: Numerical or analytical analyses were performed on seven different test specimens including blister test, 90-degree peel test, torsion test, and various cone tests. These specimens are in general subjected to complex stress fields having various amounts of Mode I, Mode II, and Mode III loads. The specimens were then constructed using polymethyl methacrylate for the adherends and a transparent polyurethane elastomer (Solithane 113) for the adhesive. This combination permitted direct observation of the bondline as load was applied. Although initial debonds as well as bond end termination singularities were present in all specimens, in some cases the debond did not initiate at the singularity points as would normally have been expected. An explanation for this behavior is presented, as well as a comparison of loading mode effect on those specimens for which the debond did propagate from a bond terminus singular point.
    Keywords: STRUCTURAL MECHANICS
    Type: International Journal of Fracture; 10; Dec. 197
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  • 45
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    Dependence of plate-bending finite element deflections and eigenvalues on Poisson's ratio (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Keywords: STRUCTURAL MECHANICS
    Type: AIAA Journal; 12; Oct. 197
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  • 46
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    Diffused optical waveguides (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: Diffused optical waveguides are studied using the modal and the ray tracing approach, with an emphasis on the case of a hollow waveguide with diffuse cladding. The properties of the guided modes are investigated in detail. The applications of these structures to optical circuits, integrated optics lasers and capillary gas lasers are discussed.
    Keywords: COMMUNICATIONS
    Type: vol. 43; July 197
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  • 47
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    The Apollo Lunar Sounder radar system (1974)
    In:  Other Sources
    Details
    Publication Date: 2011-08-16
    Description: The objectives of the Apollo 17 Lunar Sounder Experiment (ALSE) were to detect subsurface geologic structures, to generate a continuous lunar profile, and to image the moon at radar wavelengths. A three-wavelength synthetic-aperture radar (SAR) operating at 60, 20, and 2 m wavelengths was designed to attain these objectives. The design choices reflected a balance of scientific requirements versus Apollo mission and hardware constraints. The radar data from the lunar mission were recorded on photographic film in a conventional SAR format, and were returned to earth for processing. A combination of optical and digital processing and exploitation techniques was applied to the scientific interpretation of the data. Some preliminary results from the lunar mission have been obtained.
    Keywords: COMMUNICATIONS
    Type: IEEE; vol. 62
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  • 48
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    Mutual coupling in a finite planar array of circular apertures (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: Equations are presented for the calculation of the interelement mutual coupling in a finite size planar array of wave-guide-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 TE11 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.
    Keywords: COMMUNICATIONS
    Type: IEEE Transactions on Antennas and Propagation; AP-22; Mar. 197
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  • 49
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    Fracture initiation and propagation in a cylindrical shell containing an initial surface flaw (1974)
    In:  Other Sources
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    Publication Date: 2011-08-16
    Description: An attempt is made to provide the necessary analytical tools for the application of two different types of fracture criteria to shell structures. Of particular interest is the problem of fracture propagation and arrest in a cylindrical pressure vessel containing an initial surface flaw. It is assumed that the flaw has the most unfavorable geometry and orientation, namely, it is a crack lying on a meridional plane. Stress intensity factor for a part-through crack, and a surface or internal crack with a fully yielded net ligament are considered. Attention is given to constant delta curves for depressurization studies and to depressurization and crack arrest in pressure vessels.
    Keywords: STRUCTURAL MECHANICS
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  • 50
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    An overview of high temperature metal fatigue: Aspects covered by the 1973 International Conference on Creep and Fatigue (1974)
    In:  CASI
    Details
    Publication Date: 2012-05-22
    Description: A summary of papers is presented which covers the following broad aspects of high temperature metal fatigue: (1) materials development and characterization; (2) environmental factors, including air, vacuum, helium, iodine, sodium, and radiation environments; (3) general fatigue life relationships; (4) crack growth laws; (5) design code activities; and (6) design and service experience. Illustrative tables accompany the summary.
    Keywords: STRUCTURAL MECHANICS
    Type: AGARD Low Cycle High Temp. Fatigue; 47 p
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  • 51
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    Influence of noise requirements on STOL propulsion system designs (1974)
    In:  CASI
    Details
    Publication Date: 2012-05-22
    Description: The severity of proposed noise goals for STOL systems has resulted in a new design approach for aircraft propulsion systems. It has become necessary to consider the influence of the noise goal on the design of engine components, engine systems, and the integrated nacelle, separately and collectively, from the onset of the design effort. This integrated system design approach is required in order to effect an optimization of the propulsion and aircraft system. Results from extensive design studies and pertinent test programs are presented which show the effect of noise specifications on component and system design, and the trade-offs possible of noise versus configuration and performance. The design optimization process of propulsion systems for powered lift systems is presented beginning with the component level and proceeding through to the final integrated propulsion system. Designs are presented which are capable of meeting future STOL noise regulations and the performance, installation and economic penalties are assessed as a function of noise level.
    Keywords: PROPULSION SYSTEMS
    Type: AGARD V(STOL Propulsion Systems; 17 p
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  • 52
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    Identification of structural parameters from helicopter dynamic test data (1974)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: A method is presented for obtaining the mass, stiffness, and damping parameters of a linear mathematical model, having fewer degrees of freedom than the structure it represents, directly from dynamic response measurements on the actual helicopter without a priori knowledge of the physical characteristics of the fuselage. The only input information required in the formulation is the approximate natural frequency of each mode and mobility data measured proximate to these frequencies with sinusoidal force excitation applied at only one point on the vehicle. The practicality and numerical soundness of the theoretical development was demonstrated through a computer simulation of an experimental program.
    Keywords: STRUCTURAL MECHANICS
    Type: NASA. Ames Res. Center Rotorcraft Dyn.; p 239-248
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  • 53
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    Application of antiresonance theory to helicopters (1974)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: Antiresonance theory is the principle underlying nonresonant nodes in a structure, and covers both nonresonant nodes occurring naturally and those introduced by devices such as dynamic absorbers and antiresonant isolators. The dynamic antiresonant vibration isolator (DAVI) and the nodale module are examples of the applications of transfer antiresonances. It is shown that antiresonances are eigenvalues, and that they can be determined by matrix iteration. Applications of antiresonance theory to helicopter engineering problems, using the antiresonant eigenvalue equation are suggested.
    Keywords: STRUCTURAL MECHANICS
    Type: NASA. Ames Res. Center Rotorcraft Dyn.; p 101-106
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  • 54
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    Correlation of finite-element structural dynamic analysis with measured free vibration characteristics for a full-scale helicopter fuselage (1974)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: The correlation achieved with each program provides the material for a discussion of modeling techniques developed for general application to finite-element dynamic analyses of helicopter airframes. Included are the selection of static and dynamic degrees of freedom, cockpit structural modeling, and the extent of flexible-frame modeling in the transmission support region and in the vicinity of large cut-outs. The sensitivity of predicted results to these modeling assumptions are discussed. Both the Sikorsky Finite-Element Airframe Vibration analysis Program (FRAN/Vibration Analysis) and the NASA Structural Analysis Program (NASTRAN) have been correlated with data taken in full-scale vibration tests of a modified CH-53A helicopter.
    Keywords: STRUCTURAL MECHANICS
    Type: NASA. Ames Res. Center Rotorcraft Dyn.; p 67-80
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  • 55
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    Flight velocity effects on jet noise of several variations of a twelve-chute suppressor installed on a plug nozzle (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Because of the relatively high takeoff speeds of supersonic transport aircraft, it is important to know whether the flight velocity effects the noise level of suppressor nozzles. To investigate this, a modified F-106B aircraft was used to conduct a series of flyover and static tests on a 12-chute suppressor installed on an uncooled plug nozzle. Comparison of flyover and static spectra indicated that flight velocity adversely affected noise suppressions of the 12-chute configurations.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-TM-X-2918 , E-7449
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  • 56
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    FORTRAN program to generate engine inlet flow contour maps and distortion parameters (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: A computer program is presented and described that generates jet engine inlet flow contour maps and inlet flow distortion parameters. The program input consists of an array of measurements describing the flow conditions at the engine inlet. User-defined distortion parameters may be calculated.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-TM-X-2967 , E-7572
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  • 57
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    Thrust performance of isolated plug nozzles with two types of 40-spoke noise suppressor at Mach numbers from 0 to 0.45 (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Plug nozzles with two types of 40-spoke noise suppressor were tested at free-stream Mach numbers from 0 to 0.45 and over a range of nozzle pressure ratios from 1.5 to 4.0. In additon, an unsuppressed plug nozzle and a Supersonic Tunnel Association nozzle were also tested to provide baseline levels of thrust performance. The unsuppressed plug nozzle had an efficiency of 98 percent at an assumed takeoff pressure ratio of 3.0 and at Mach 0.36. At the same condition the suppressor nozzles had efficiencies of approximately 83.5 percent.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-TM-X-2951 , E-7541
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  • 58
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    Simulation study of communication link for Pioneer Saturn/Uranus atmospheric entry probe (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: A digital simulation is presented for a candidate modem in a modeled atmospheric scintillation environment with Doppler, Doppler rate, and signal attenuation typical of the radio link conditions for an outer planets atmospheric entry probe. The results indicate that the signal acquisition characteristics and the channel error rate are acceptable for the system requirements of the radio link. The simulation also outputs data for calculating other error statistics and a quantized symbol stream from which error correction decoding can be analyzed.
    Keywords: COMMUNICATIONS
    Type: NASA-CR-114739
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  • 59
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    Flight velocity effects on jet noise of several variations of a 48-tube suppressor installed on a plug nozzle (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Because of the relatively high takeoff speeds of supersonic transport aircraft, it is important to know if the flight velocity affects the noise level of suppressor nozzles. To investigate this, a modified F-106B aircraft was used to conduct a series of flyover and static tests on a 48-tube suppressor installed on an uncooled plug nozzle. Comparison of flyover and static spectra indicated that flight velocity had little effect on the noise suppression of the 48-tube suppressor configuration. However, flight velocity adversely affected noise suppression of the 48-tube suppressor with an acoustic shroud and plug installed.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-TM-X-2919 , E-7513
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  • 60
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    SERT C project study (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: The SERT C (Space Electric Rocket Test - C) project study defines a spacecraft mission that would demonstrate the technology readiness of ion thruster systems for primary propulsion and station keeping applications. As a low cost precursor, SERT C develops the components and systems required for subsequent Solar Electric Propulsion (SEP) applications. The SERT C mission requirements and preliminary spacecraft and subsystem design are described.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-TM-X-71508
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  • 61
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    Transonic single-mode flutter and buffet of a low aspect ratio wing having a subsonic airfoil shape (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Transonic flutter and buffet results obtained from wind-tunnel tests of a low aspect ratio semispan wing model are presented. The tests were conducted to investigate potential transonic aeroelastic problems of vehicles having subsonic airfoil sections. The model employed NACA 00XX-64 airfoil sections in the streamwise direction and had a 14 deg leading edge sweep angle. Aspect ratio, and average thickness were 4.0, 0.35, and 8 percent, respectively. The model was tested at Mach numbers from 0.6 to 0.95 at angles of attack from 0 deg to 15 deg. Two zero lift flutter conditions were found that involved essentially single normal mode vibrations. With boundary layer trips on the model, flutter occurred in a narrow Mach number range centered at about Mach 0.90. The frequency and motion of this flutter were like that of the first normal mode vibration. With the trips removed flutter occurred at a slightly high Mach number but in a mode strongly resembling that of the second normal mode.
    Keywords: STRUCTURAL MECHANICS
    Type: NASA-TN-D-7346 , A-4966
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  • 62
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    Transverse vibrations of non-uniform beams (1974)
    In:  Other Sources
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    Publication Date: 2019-06-27
    Description: The free vibrations of elastic beams with nonuniform characteristics are investigated theoretically by a new method. The new method is seen to combine the advantages of a finite element approach and of a Rayleigh-Ritz analysis. Comparison with the known analytical results for uniform beams shows good convergence of the method for natural frequencies and modes. For internal shear forces and bending moments, the rate of convergence is less rapid. Results from experiments conducted with a cantilevered helicopter blade with strong nonuniformities and also from alternative theoretical methods, indicate that the theory adequately predicts natural frequencies and mode shapes. General guidelines for efficient use of the method are presented.
    Keywords: STRUCTURAL MECHANICS
    Type: Journal of Sound and Vibration; 37; Dec. 22
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  • 63
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    Two-dimensional cold-air cascade study of a film-cooled turbine stator blade. 1: Experimental results of pressure-surface film cooling tests (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: The effect of film coolant ejection from the pressure side of a stator blade was determined in a two-dimensional cascade. Stator exit surveys were made for each of six rows of coolant holes. Successive multirow tests were made with two, three, four, five, and six rows of coolant holes open. The results of the multirow tests are compared with the predicted multirow performance obtained by adding the single-row data. Results are presented in terms of stator primary-air efficiency as a function of coolant fraction.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-TM-X-3045 , E-7817
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  • 64
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    Non-linear behavior of fiber composite laminates (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: The non-linear behavior of fiber composite laminates which results from lamina non-linear characteristics was examined. The analysis uses a Ramberg-Osgood representation of the lamina transverse and shear stress strain curves in conjunction with deformation theory to describe the resultant laminate non-linear behavior. A laminate having an arbitrary number of oriented layers and subjected to a general state of membrane stress was treated. Parametric results and comparison with experimental data and prior theoretical results are presented.
    Keywords: STRUCTURAL MECHANICS
    Type: NASA-CR-2313 , TFR/7309
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  • 65
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    Failure criteria for viscoelastic materials (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Research projects concerned with developing a theory of fracture of materials are discussed. The effects of the geometry of the structure and the loads acting on the structure as they influence the failure process are analyzed. The effects of the viscoelastic deformation characteristics of the bulk elastomer on failure behavior are examined. Additional material parameters which control the fracture process are identified.
    Keywords: STRUCTURAL MECHANICS
    Type: NASA-CR-138125 , GALCIT-120
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    Advance development of a technique for characterizing the thermomechanical properties of thermally stable polymers (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: The torsional braid experiment has been interfaced with a centralized hierarchical computing system for data acquisition and data processing. Such a system, when matched by the appropriate upgrading of the monitoring techniques, provides high resolution thermomechanical spectra of rigidity and damping, and their derivatives with respect to temperature.
    Keywords: STRUCTURAL MECHANICS
    Type: NASA-CR-138123
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    Basic performance of a multilayer insulation system containing 20 to 160 layers (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: An experimental investigation was conducted to determine the thermal effectiveness of an aluminized Mylar-silk net insulation system containing up to 160 layers. The experimentally measured heat flux was compared with results predicted by using (1) a previously developed semi-empirical equation and (2) an effective-thermal-conductivity value. All tests were conducted at a nominal hot-boundary temperature of 294 K (530 R) with liquid hydrogen as the heat sink. The experimental results show that the insulation performed as expected and that both the semi-empirical equation and effective thermal conductivity of a small number of layers were adequate in predicting the thermal performance of a large number of layers of insulation.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-TN-D-7659 , E-7815
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    Low cost ground receiving systems for television signals from high-powered communications satellites. Volume 2: Parts list and engineering drawings (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Parts lists for the 2.25 GHz indoor- and antenna-unit assemblies are followed by drawings that constitute the drafting package for three converter types and the tunnel diode amplifier.
    Keywords: COMMUNICATIONS
    Type: NASA-CR-120933
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    Task 60 test report, evaluation of IRIG-A 21 channel constant bandwith FM multiplexer for shuttle development flight instrumentation (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: A frequency modulated (FM) multiplexer, consisting of 21 IRIG-A constant bandwidth (CBW) voltage-controlled oscillators (VCO's) was tested to determine its suitability for use in multiplexing 21 data signals which have frequency ranges of dc to 2 kHz. Tests were preformed with the composite signal, consisting of the mixed outputs of the 21 VCO's connected directly to a set of subcarrier discriminators, with the signal recorded on magnetic tape and played back through the discriminators and with the signal transmitted by a frequency-modulated FM S-band radio frequency RF transmitter to a FM receiver and through the subcarrier discriminators. Tape speed flutter was induced to determine the reduction in flutter noise which can be obtained by the tape speed compensation equipment. The RF transmission test included transmitting the composite signal at a nominal RF received signal of -73 dbm and at RF levels of -83 and -86 dbm.
    Keywords: COMMUNICATIONS
    Type: NASA-CR-134304 , LEC-3558 , JSC-09017
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    Analysis of laminated, composite, circular cylindrical shells with general boundary conditions (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: This report develops: (1) a refined approximate theory for the static and dynamic analyses of finite, laminated, composite, circular cylindrical shells with general boundary conditions; (2) an exact three-dimensional analysis of simply supported, laminated, composite, circular cylindrical shells, and (3) a thin-shell theory for laminated, composite, circular cylindrical shells. In the refined approximate theory the displacements are assumed piecewise linear across the thickness and the effects of transverse shear deformations and transverse normal stress are included. A variational approach is followed to obtain the governing differential equations and boundary conditions. A general solution of the governing differential equations is also presented. The results obtained by using the refined approximate theory and the thin-shell theory are compared with the exact results for the case of free vibrations of simply supported, laminated, composite, circular cylindrical shells. The refined approximate theory is very accurate, even for thick shells with short nodal distances, whereas thin-shell theory is reasonably accurate only for thin shells at moderate nodal distances and wave number less than 2.
    Keywords: STRUCTURAL MECHANICS
    Type: NASA-TR-R-412 , L-8828
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    Holographic nondestructive tests performed on composite samples of ceramic-epoxy-fiberglass sandwich structure (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: When a hologram storing more than one wave is illuminated with coherent light, the reconstructed wave fronts interfere with each other or with any other phase-related wave front derived from the illuminating source. This multiple wave front comparison is called holographic interferometry, and its application is called holographic nondestructive testing (HNDT). The theoretical aspects of HNDT techniques and the sensitivity of the holographic system to the geometrical placement of the optical components are briefly discussed. A unique HNDT system which is mobile and possesses variable sensitivity to stress amplitude is discribed, the experimental evidence of the application of this system to the testing of the hidden debonds in a ceramic-epoxy-fiberglass structure used for sample testing of the radome of the Pershing missile system is presented.
    Keywords: STRUCTURAL MECHANICS
    Type: NASA-TR-R-430 , M-461
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    Procedures for experimental measurement and theoretical analysis of large plastic deformations (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Theoretical equations are derived and analytical procedures are presented for the interpretation of experimental measurements of large plastic strains in the surface of a plate. Orthogonal gage lengths established on the metal surface are measured before and after deformation. The change in orthogonality after deformation is also measured. Equations yield the principal strains, deviatoric stresses in the absence of surface friction forces, true stresses if the stress normal to the surface is known, and the orientation angle between the deformed gage line and the principal stress-strain axes. Errors in the measurement of nominal strains greater than 3 percent are within engineering accuracy. Applications suggested for this strain measurement system include the large-strain-stress analysis of impact test models, burst tests of spherical or cylindrical pressure vessels, and to augment small-strain instrumentation tests where large strains are anticipated.
    Keywords: STRUCTURAL MECHANICS
    Type: NASA-TM-X-3027 , E-7661
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    Analysis of three-point-bend test for materials with unequal tension and compression properties (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: An analysis capability is described for the three-point-bend test applicable to materials of linear but unequal tensile and compressive stress-strain relations. The capability consists of numerous equations of simple form and their graphical representation. Procedures are described to examine the local stress concentrations and failure modes initiation. Examples are given to illustrate the usefulness and ease of application of the capability. Comparisons are made with materials which have equal tensile and compressive properties. The results indicate possible underestimates for flexural modulus or strength ranging from 25 to 50 percent greater than values predicted when accounting for unequal properties. The capability can also be used to reduce test data from three-point-bending tests, extract material properties useful in design from these test data, select test specimen dimensions, and size structural members.
    Keywords: STRUCTURAL MECHANICS
    Type: NASA-TN-D-7572 , E-7544
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    FORTRAN 4 programs for summarization and analysis of fracture trace and lineament patterns (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Systematic and detailed analysis of lineament and fracture trace patterns has long been neglected because of the large number of observations involved in such an analysis. Three FORTRAN 4 programs were written to facilitate this manipulation. TRANSFORM converts the initial fracture map data into a format compatible with AZMAP, whose options allow repetitive manipulation of the data for optimization of the analysis. ROSE creates rose diagrams of the fracture patterns suitable for map overlays and tectonic interpretation. Examples are given and further analysis techniques using output from these programs are discussed.
    Keywords: STRUCTURAL MECHANICS
    Type: NASA-TM-X-70596 , X-644-74-3
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    Sensitivity analysis of torsional vibration characteristics of helicopter rotor blades. Part 2: Aerodynamics and sensitivity analysis (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: A theoretical investigation of dynamic response characteristics of rotor blades was carried out with special emphasis on torsional degrees-of-freedom. Coupled equations of motion for flapwise bending and torsion were formulated at varying azimuth positions for rotor blades with noncollinear aerodynamic, elastic and mass axes. Both structural and aerodynamic mass, damping and stiffness coefficients were included. The variations of a sample blade at different flight conditions were investigated from these equations. The obtained numerical results were illustrated. The sensitivity of overall blade vibration characteristics to torsional oscillations was also investigated from the equations of motion for the sample blade. The illustrated results show the importance of torsional degrees-of-freedom in rotor blade analysis. Various possibilities of improving the overall response by tuning blade geometric, structural and aerodynamic characteristics are discussed.
    Keywords: STRUCTURAL MECHANICS
    Type: NASA-CR-2380
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    Solar array study for solar electric propulsion spacecraft for the Encke rendezvous mission (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: The work is described which was performed on the design, analysis and performance of a 20 kW rollup solar array capable of meeting the design requirements of a solar electric spacecraft for the 1980 Encke rendezvous mission. To meet the high power requirements of the proposed electric propulsion mission, solar arrays on the order of 186.6 sq m were defined. Because of the large weights involved with arrays of this size, consideration of array configurations is limited to lightweight, large area concepts with maximum power-to-weight ratios. Items covered include solar array requirements and constraints, array concept selection and rationale, structural and electrical design considerations, and reliability considerations.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-CR-136860 , JPL-TM-33-668
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  • 77
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    Performance of a hydrogen burner to simulate air entering scramjet combustors (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Tests were conducted to determine the performance of a hydrogen burner used to produce a test gas that simulates air entering a scramjet combustor at various flight conditions. The test gas simulates air in that it duplicates the total temperature, total pressure, and the volume fraction of oxygen of air at flight conditions. The main objective of the tests was to determine the performance of the burner as a function of the effective exhaust port area. The conclusions were: (1) pressure oscillations of the chugging type were reduced in amplitude to plus or minus 2 percent of the mean pressure level by proper sizing of hydrogen, oxygen, and air injector flow areas; (2) combustion efficiency remained essentially constant as the exhaust port area was increased by a factor of 3.4; (3) the mean total temperature determined from integrating the exit radial gas property profiles was within plus or minus 5 percent of the theoretical bulk total temperature; (4) the measured exit total temperature profile had a local peak temperature more than 30 percent greater than the theoretical bulk total temperature; and (5) measured heat transfer to the burner liner was 75 percent of that predicted by theory based on a flat radial temperature profile.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-TN-D-7567 , L-9363
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    Experimental investigation of a 4 and 1/2 stage turbine with very high stage loading factor. 2: Turbine performance (1974)
    In:  CASI
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    Publication Date: 2019-06-27
    Description: The experimental test program results of a 4 1/2-stage turbine with a very high stage loading factor are presented. A four-stage turbine was tested with and without outlet turning vanes. The 4 1/2-stage turbine achieved a design point total-to-total efficiency of 0.853. The outlet turning vane design point performance was 0.4 percent of the overall 4 1/2-stage turbine efficiency. Tests were conducted at various levels of Reynolds number and indicated decreases in turbine efficiency and equivalent weight flow with decreasing Reynolds number.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-CR-2363 , R73AEG163
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    Single-stage experimental evaluation of tandem-airfoil rotor and stator blading for compressors. Part 7: Data and performance for stage E (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: An axial flow compressor stage, having tandem airfoil blading, was designed for zero rotor prewhirl, constant rotor work across the span, and axial discharge flow. The stage was designed to produce a pressure ratio of 1.265 at a rotor tip velocity of 757 ft/sec. The rotor has an inlet hub/tip ratio of 0.8. The design procedure accounted for the rotor inlet boundary layer and included the effects of axial velocity ratio and secondary flow on blade row performance. The objectives of this experimental program were (1) to obtain performance with uniform and distorted inlet flow for comparison with the performance of a stage consisting of single-airfoil blading designed for the same vector diagrams and (2) to evaluate the effectiveness of accounting for the inlet boundary layer, axial velocity ratio, and secondary flows in the stage design.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-CR-134529 , FR-5955
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    Exploratory tests of two strut fuel injectors for supersonic combustion (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Results of supersonic mixing and combustion tests performed with two simple strut injector configurations, one with parallel injectors and one with perpendicular injectors, are presented and analyzed. Good agreement is obtained between static pressure measured on the duct wall downstream of the strut injectors and distributions obtained from one-dimensional calculations. Measured duct heat load agrees with results of the one-dimensional calculations for moderate amounts of reaction, but is underestimated when large separated regions occur near the injection location. For the parallel injection strut, good agreement is obtained between the shape of the injected fuel distribution inferred from gas sample measurements at the duct exit and the distribution calculated with a multiple-jet mixing theory. The overall fraction of injected fuel reacted in the multiple-jet calculation closely matches the amount of fuel reaction necessary to match static pressure with the one-dimensional calculation. Gas sample measurements with the perpendicular injection strut also give results consistent with the amount of fuel reaction in the one-dimensional calculation.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-TN-D-7581 , L-9428
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    Integrated source and channel encoded digital communications system design study (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Studies on the digital communication system for the direct communication links from ground to space shuttle and the links involving the Tracking and Data Relay Satellite (TDRS). Three main tasks were performed:(1) Channel encoding/decoding parameter optimization for forward and reverse TDRS links,(2)integration of command encoding/decoding and channel encoding/decoding; and (3) modulation coding interface study. The general communication environment is presented to provide the necessary background for the tasks and to provide an understanding of the implications of the results of the studies.
    Keywords: COMMUNICATIONS
    Type: NASA-CR-134183 , R7401-2
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    Assembly and analysis of fragmentation data for liquid propellant vessels (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Fragmentation data was assembled and analyzed for exploding liquid propellant vessels. These data were to be retrieved from reports of tests and accidents, including measurements or estimates of blast yield, etc. A significant amount of data was retrieved from a series of tests conducted for measurement of blast and fireball effects of liquid propellant explosions (Project PYRO), a few well-documented accident reports, and a series of tests to determine auto-ignition properties of mixing liquid propellants. The data were reduced and fitted to various statistical functions. Comparisons were made with methods of prediction for blast yield, initial fragment velocities, and fragment range. Reasonably good correlation was achieved. Methods presented in the report allow prediction of fragment patterns, given type and quantity of propellant, type of accident, and time of propellant mixing.
    Keywords: STRUCTURAL MECHANICS
    Type: NASA-CR-134538
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    Stress anisotropy and concentration effects in high pressure measurements (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Sodium chloride is used as an internal pressure standard in high pressure research. Possible corrections are discussed which are needed in the calibration of this standard due to the independent effects of stress anisotropy and stress concentration in pressure vessels. The first is due to the lack of a truly hydrostatic state of stress in solid state pressure vessels. The second is due to the difference in the compressibilities between the pressure transmitting substances (sodium chloride) and a stiffer test specimen. These two corrections are then combined and a total correction, as a function of measured pressure, is discussed for two systems presently in use. The predicted value of the combined effect is about 5-10% of the pressure at 30 GPa.
    Keywords: STRUCTURAL MECHANICS
    Type: NASA-CR-142600 , REPT-2345
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    Elastic moduli of precompressed pyrophyllite used in ultrahigh pressure research (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: The propagation of ultrasonic pulses in pyrophyllite specimens was studied to determine the effect of specimen precompression on the measured elastic moduli. Measurements were made at room pressure and, for the precompressed specimens, to pressures of 3 kbar. Pyrophyllite was found to be elastically anisotropic, apparently the result of the fabric present in our material. The room pressure adiabatic bulk modulus as measured on specimens made of isostatically compacted powered pyrophyllite was determined to be 96.1 kbar. The wave speeds of ultrasonic pulses in pyrophyllite were found to decrease with increasing specimen precompression. A limiting value of precompression was found, above which no further decrease in wave speed was observed. For the shear wave speeds this occurs at 10 kbar while for the longitudinal wave at 25 kbar. In the limit, the shear waves propagate 20% slower than in the unprecompressed samples; for the longitudinal wave the difference is 30%.
    Keywords: STRUCTURAL MECHANICS
    Type: NASA-CR-142598 , REPT-2366
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    Contact and crack problems for an elastic wedge (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: The contact and the crack problems for an elastic wedge of arbitrary angle are considered. The problem is reduced to a singular integral equation which, in the general case, may have a generalized Cauchy kernel. The singularities under the stamp as well as at the wedge apex were studied, and the relevant stress intensity factors are defined. The problem was solved for various wedge geometries and loading conditions. The results may be applicable to certain foundation problems and to crack problems in symmetrically loaded wedges in which cracks initiate from the apex.
    Keywords: STRUCTURAL MECHANICS
    Type: NASA-CR-132640
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    Jet engine exhaust noise due to rough combustion and nonsteady aerodynamic sources (1974)
    In:  Other Sources
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    Publication Date: 2019-06-27
    Keywords: PROPULSION SYSTEMS
    Type: Acoustical Society of America; vol. 56
    Format: text
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    Effects of turbulence in a planetary atmosphere on radio occultation (1974)
    In:  Other Sources
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    Publication Date: 2019-06-27
    Description: A formulation is given for the correlation functions for the log-amplitude and phase fluctuations of both spherical and plane waves propagating in a turbulent medium whose correlation function for refractive index fluctuations is described by the product of a function of the average coordinate and a function of the difference coordinate. The results are applied to radio occultation of a flyby space probe by the atmosphere of Venus, assuming that the turbulence in the atmosphere exists as a layer, that it is localized, isotropic, and smoothly varying, and that the localized turbulence is described by the Kolmogorov spectrum. Closed-form solutions for both variances and frequency spectra of the log-amplitude and phase fluctuations are obtained using Rytov's method, and it is seen that the shape of the frequency spectra depends greatly on the characteristics and extent of the turbulence.
    Keywords: COMMUNICATIONS
    Type: IEEE Transactions on Antennas and Propagation; AP-22; July 197
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    The interpretation of ionospheric radio drift measurements. VII - Diffraction methods applied to E-region echo fading: Evidence of a focusing model (1974)
    In:  Other Sources
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    Publication Date: 2019-06-27
    Keywords: COMMUNICATIONS
    Type: Journal of Atmospheric and Terrestrial Physics; 36; May 1974
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    Properties of cutoff corrugated surfaces for corrugated horn design (1974)
    In:  Other Sources
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    Publication Date: 2019-06-27
    Description: Corrugated horns involve a junction between the corrugated surface and a conducting ground plane. Proper horn design requires an understanding of the electromagnetic properties of the corrugated surface and this junction. An integral equation solution has been used to study the influence of corrugation density and tooth thickness on the power loss, surface current, and the scattering from a ground plane/corrugated surface junction.
    Keywords: COMMUNICATIONS
    Type: IEEE Transactions on Antennas and Propagation; AP-22; Mar. 197
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  • 90
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    Derivatives of eigenvalues and eigenvectors for a general matrix (1974)
    In:  Other Sources
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    Publication Date: 2019-06-27
    Description: Expressions are obtained for the derivatives of the eigenvalues and eigenvectors which are expressions of only one left-hand and one right-hand eigenvector. The approach described makes use of a Choleski decomposition or some other decomposition method. The method may be extended to find any order of derivative of the eigenvalue and eigenvector. The expressions obtained for finding the derivatives of eigenvalues and eigenvectors for nonself-adjoint systems may be applied to self-adjoint systems.
    Keywords: STRUCTURAL MECHANICS
    Type: AIAA Journal; 12; May 1974
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  • 91
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    An experimental-theoretical study of free vibrations of plates on elastic point supports (1974)
    In:  Other Sources
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    Publication Date: 2019-06-27
    Description: A theoretical and experimental study is made to investigate the effect on plate vibrations of varying the stiffness of corner elastic point supports. An experiment is conducted in which the bending stiffness of horizontal beams is used to support a square plate at its four corners. The stiffness of these supports can be varied over such a range that the plate fundamental frequency is lowered to 40% of the rigid support frequency. The variation with support stiffness of the frequencies of the first eight plate modes is measured and is compared with results from a theoretical model in which a Rayleigh-Ritz analysis is used which approximates the plate mode shapes as products of free-free beam modes. The elastic point supports are modeled both as massless translational springs and springs with tip masses, which are included to better represent the experimental supports.
    Keywords: STRUCTURAL MECHANICS
    Type: Journal of Sound and Vibration; 32; Feb. 22
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    Application of an integral equation formulation to the prediction of space shuttle annular slot antenna radiation patterns (1974)
    In:  Other Sources
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    Publication Date: 2019-06-27
    Description: Pitch and roll plane radiation patterns computed by use of an integral equation formulation are presented for a space shuttle annular slot communications antenna. The excellent agreement between computed patterns and experimental patterns obtained from 1/35 scale models supports the use of this method as a design tool for similar spacecraft/aircraft antenna applications.
    Keywords: COMMUNICATIONS
    Type: IEEE Transactions on Antennas and Propagation; AP-22; Jan. 197
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  • 93
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    Design manual: Oxygen Thermal Test Article (OTTA) (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: The characteristics of a cryogenic tank for storing liquid hydrogen, nitrogen, oxygen, methane, or helium for an extended period of time with minimum losses are discussed. A description of the tank and control module, assembly drawings and details of major subassemblies, specific requirements controlling development of the system, thermal concept considerations, thermal analysis methods, and a record of test results are provided. The oxygen thermal test article thermal protection system has proven that the insulation system for cryogenic vessels is effective.
    Keywords: STRUCTURAL MECHANICS
    Type: NASA-CR-140209 , ER15961
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    Research on the elastic stability of large shells (1974)
    In:  CASI
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    Publication Date: 2019-06-27
    Description: Tests were conducted to determine the elastic stability of large shell structures. The configuration of the shells and the instrumentation used in the measurements are described. The testing procedures are explained. Results of the stress analysis are plotted in polar graph form to show the areas of strain in micro inches at the outer surface of the skin and the inner lip of the stringer.
    Keywords: STRUCTURAL MECHANICS
    Type: NASA-CR-139665 , SAPR-6
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    Eight cm technology thruster development (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: A structural integrated ion thruster with 8-cm beam diameter (SIT-8) was developed for attitude control and stationkeeping of synchronous satellites. As optimized, the system demonstrates a thrust T=1.14 mlb (not corrected for beam V sub B = 1200 V (I sub sp = 2200 sec) total propellant utilization efficiency nu sub u = 59.8% (is approximately 72% without auxiliary pulse-igniter electrode), and electrical efficiency n sub E 61.9%. The thruster incorporates a wire-mesh anode and tantalum cover surfaces to control discharge chamber flake formation and employs an auxiliary pulse-igniter electrode for hollow-cathode ignition. When the SIT-8 is integrated with the compatible SIT-5 propellant tankage, the system envelope is 35 cm long by 13 cm flange bolt circle with a mass of 9.8 kg including 6.8 kg of mercury propellant. Two thrust vectoring systems which generate beam deflections in two orthogonal directions were also developed under the program and tested with the 8-cm thruster. One system vectors the beam over + or - 10 degrees by gimbaling of the entire thruster (not including tankage), while the other system vectors the beam over + or - 7 degrees by translating the accel electrode relative to the screen electrode.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-CR-134685
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    Overall and blade-element performance of a 1.20-pressure-ratio fan stage at design blade setting angle (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: A 51-cm-diam. model of a short-haul fan stage was tested. Surveys of the air flow conditions ahead of the rotor, between the rotor and stator, and behind the stator were made over the stable operating range of the stage. At the design speed of 213.3 m/sec and weight flow of 26.7 kg/sec, the stage pressure ratio and efficiency are 1.18 and 0.87, respectively. The rotor peak efficiency of 0.92 occurred at flow rate of 30.5 kg/sec. Peak stage efficiency of 0.09 was obtained at 110 percent speed at a pressure ratio of 1.218 and a weight flow of 30.2 kg/sec. Maximum stage pressure ratio is 1.269 at 120 percent speed.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-TM-X-3101 , E-7791
    Format: application/pdf
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    NASA TECHNICAL REPORTS
  • 97
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    Unknown
    Task 12 data dump (phase 2) OME integrated thrust chamber test report (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: The characteristics and performance of the orbit maneuvering engine for the space shuttle are discussed. Emphasis is placed on the regeneratively cooled thrust chamber of the engine. Tests were conducted to determine engine operating parameters during the start, shutdown, and restart. Characteristics of the integrated thrust chamber and the performance and thermal conditions for blowdown operation without supplementary boundary layer cooling were investigated. The results of the test program are presented.
    Keywords: PROPULSION SYSTEMS
    Type: NASA-CR-140250 , ASR74-229
    Format: application/pdf
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    NASA TECHNICAL REPORTS
  • 98
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    Unknown
    Abating exhaust noises in jet engines (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: A noise abating improvement for jet engines including turbojets, turbofans, turboprops, ramjets, scramjets, and hybrid jets is introduced. A provision is made for an apparatus in the primary and/or secondary flow streams of the engines; the apparatus imparts to the exhaust gases a component rotation or swirl about the engine's longitudinal axis. The rotary component in the exhaust gases causes a substantial suppression of sound energy build up normally produced by an axial flow exhaust system.
    Keywords: COMMUNICATIONS
    Format: application/pdf
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    NASA TECHNICAL REPORTS
  • 99
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    Unknown
    Preparing oxidizer coated metal fuel particles (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: A solid propellant composition of improved efficiency is described which includes an oxidizer containing ammonium perchlorate, and a powered metal fuel, preferably aluminum or beryllium, in the form of a composite. The metal fuel is contained in the crystalline lattice framework of the oxidizer, as well as within the oxidizer particles, and is disposed in the interstices between the oxidizer particles of the composition. The propellant composition is produced by a process comprising the crystallization of ammonium perchlorate in water, in the presence of finely divided aluminum or beryllium. A suitable binder is incorporated in the propellant composition to bind the individual particles of metal with the particles of oxidizer containing occluded metal.
    Keywords: PROPULSION SYSTEMS
    Format: application/pdf
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    NASA TECHNICAL REPORTS
  • 100
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    Unknown
    Design of a 12 channel fm microwave receiver (1974)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: The design, fabrication, and performance of elements of a low cost FM microwave satellite ground station receiver is described. It is capable of accepting 12 contiguous color television equivalent bandwidth channels in the 11.72 to 12.2 GHz band. Each channel is 40 MHz wide and incorporates a 4 MHz guard band. The modulation format is wideband FM and the channels are frequency division multiplexed. Twelve independent CATV compatible baseband outputs are provided. The overall system specifications are first discussed, then consideration is given to the receiver subsystems and the signal branching network.
    Keywords: COMMUNICATIONS
    Type: NASA-CR-140056 , R(T)-74/2
    Format: application/pdf
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    NASA TECHNICAL REPORTS
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