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  • General Chemistry  (8.394)
  • BIOSCIENCES  (1.698)
  • STRUCTURAL MECHANICS  (1.510)
  • Cell & Developmental Biology
  • 1970-1974  (8.908)
  • 1930-1934  (4.019)
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  • 1
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    Space and man (1974)
    In:  CASI
    Details
    Publikationsdatum: 2006-01-11
    Beschreibung: The effects of man's entry into space on changes in economics and technology, politics and law, science, philosophy, and art are considered. A single world economy, extracting from the natural resources of the moon and other cosmic bodies raw materials and energy, will avoid terrestrial limitations and improve society by eliminating the inequalities of economic and social status. However, a spacecraft for interplanetary travel require thermonuclear engines that achieve an escape velocity of 0.1 times the speed of light in order to allow an astronaut stellar expedition corresponding to the active life of a single generation.
    Schlagwort(e): BIOSCIENCES
    Materialart: Inhabited Space, Pt. 2 (NASA-TT-F-820); p 128-134
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  • 2
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    Detection of life in space (1974)
    In:  CASI
    Details
    Publikationsdatum: 2006-01-11
    Beschreibung: The selection of spacecraft experiments and equipment to detect extraterrestrial life outside earth centers on observations of chemical compounds similar to amino acids and proteins, on signs of metabolism in the form of nutrient absorption, and life form impressions in fossiles or signs of civilization.
    Schlagwort(e): BIOSCIENCES
    Materialart: Inhabited Space, Pt. 2 (NASA-TT-F-820; p 42-52
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  • 3
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    Space psychology (1974)
    In:  CASI
    Details
    Publikationsdatum: 2006-01-11
    Beschreibung: Psychological selection of astronauts considers mental responses and adaptation to the following space flight stress factors: (1) confinement in a small space; (2) changes in three dimensional orientation; (3) effects of altered gravity and weightlessness; (4) decrease in afferent nerve pulses; (5) a sensation of novelty and danger; and (6) a sense of separation from earth.
    Schlagwort(e): BIOSCIENCES
    Materialart: Inhabited Space, Pt. 2 (NASA-TT-F-820); p 29-41
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  • 4
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    Life in space (1974)
    In:  CASI
    Details
    Publikationsdatum: 2006-01-11
    Beschreibung: Biotechnological aspects of manned space flight are reviewed and the basic biological problems of training and sustaining man in interplanetary flights are elaborated.
    Schlagwort(e): BIOSCIENCES
    Materialart: Inhabited Space, Pt. 2 (NASA-TT-F-820); p 17-28
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  • 5
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    Noise and vibration level reduction by covering metal structures with layers of damping materials (1974)
    In:  CASI
    Details
    Publikationsdatum: 2006-01-11
    Beschreibung: One of the most important methods of reducing the noise and vibration level is the damping of the secondary sources, such as metal plates, often used in vehicle structures, by means of covering materials with high internal viscosity. Damping layers are chosen at an optimum thickness corresponding to the frequency and temperature range in which a certain structure works. The structure's response corresponding to various real situations is analyzed by means of a measuring chain including electroacoustical or electromechanical transducers. The experimental results provide the dependence of the loss factor and damping transmission coefficient as a function of the damping layer thickness or of the frequency for various viscoelastic covering materials.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 246-253
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  • 6
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    Vibration and recoil control of pneumatic hammers (1974)
    In:  CASI
    Details
    Publikationsdatum: 2006-01-11
    Beschreibung: Vibration sources are described for pneumatic hammers used in the mining industry (pick hammers), in boiler shops (riveting hammers), etc., bringing to light the fact that the principal vibration source is the variation in air pressure inside the cylinder. The present state of the art of vibration control of pneumatic hammers as it is practiced abroad, and the solutions adopted for this purpose, are discussed. A new type of pneumatic hammer with a low noise and vibration level is presented.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 79-84
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  • 7
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    Vibration control in forge hammers (1974)
    In:  CASI
    Details
    Publikationsdatum: 2006-01-11
    Beschreibung: Special measures are discussed for calculating, designing and executing a forge hammer foundation, so that the vibrations that occur during its working will not be transmitted to neighboring machinery, workrooms and offices. These vibrations are harmful to the workers near the forge hammer.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 73-78
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  • 8
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    Experimental determination of the vibration level in 5,100 kW electric locomotive assemblies (1974)
    In:  CASI
    Details
    Publikationsdatum: 2006-01-11
    Beschreibung: Because of the high vibration level occurring during the running of electric locomotives, mechanical defects occur in the control mechanisms of auxiliary services. This fact has given rise to the necessity of determining the values of these vibrations in electric locomotives during their running. Measurements were conducted on the Craiova-Drobeta-Turnu Severin line, and measures to reduce the vibration level in electric locomotives were instituted.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 50-54
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  • 9
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    Random vibrations of linear viscoelastic beams with lumped masses (1974)
    In:  CASI
    Details
    Publikationsdatum: 2006-01-11
    Beschreibung: A method is presented of determining the mean square transversal deflection of an isotropic and homogeneous linear viscoelastic beam having a certain number of lengthwise distributed lumped masses. It is assumed that the beam is acted upon by a stationary random process uniformly distributed along the beam. The method is useful in vibration level control by means of additional lumped masses.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 36-42
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  • 10
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    Random vibrations of quadratic damping systems (1974)
    In:  CASI
    Details
    Publikationsdatum: 2006-01-11
    Beschreibung: An oscillating system with quadratic damping subjected to white noise excitation is replaced by a nonlinear, statistically equivalent system for which the associated Fokker-Planck equation can be exactly solved. The mean square responses are calculated and the optimum damping coefficient is determined with respect to the minimum mean square acceleration criteria. An application of these results to the optimization of automobile suspension damping is given.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 29-35
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  • 11
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    The response of many-storied structures under seismic actions (1974)
    In:  CASI
    Details
    Publikationsdatum: 2006-01-11
    Beschreibung: A seismic action which is characterized by the acceleration function of the seismic motion is analyzed. The equations of motion in the direction of the seismic action are determined for a completely rigid ground and for a ground with linear deformability characteristics (rotation deformability). The equation for the rotation motion is derived by considering elastic and viscoelastic properties of the foundation ground. The differential equations are written by treating the mechanical model of a many-storied structure as a fixed vertical beam with a uniformly distributed mass as well as with concentrated masses on each floor.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 43-49
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  • 12
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    Insulation of nonlinear and random vibrations in the mining industry (1974)
    In:  CASI
    Details
    Publikationsdatum: 2006-01-11
    Beschreibung: The insulation of nonlinear and random vibrations is considered for some ore preparing and sorting implements: rotary crushers, resonance screens, hammer mills, etc. The appearance of subharmonic vibrations is analyzed, and the conditions for their appearance are determined. A method is given for calculating the insulation of these vibrations by means of elastic elements made of rubber. The insulation of the random vibrations produced by Symons crushers is calculated by determining the transmissability and deformation of the insulation system for a narrow band random response.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 22-28
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  • 13
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    A mathematical model for storied buildings subjected to automatic loom stresses (1974)
    In:  CASI
    Details
    Publikationsdatum: 2006-01-11
    Beschreibung: Expressions are derived for the displacements of a many storied building subjected to the action of classical weaving looms located at different levels of the building. The building is regarded as a vertical fixed beam with a uniformly distributed mass as well as concentrated masses at each level. The calculation relations are obtained on the assumption of harmonic variation of the forces acting at each level as well as the assumption of narrow band stationary random excitatory forces.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 15-21
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  • 14
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    Study of vibrations produced by a vibrating beam used for vibrating concretes (1974)
    In:  CASI
    Details
    Publikationsdatum: 2006-01-11
    Beschreibung: For compacting concretes in building, vibrating beams are used. The vibrations are generated by inertial vibrators, and the beam is normally displaced by the operator by means of a handle that is elastically fastened to the beam by means of rubber pads. Considered are vibrations transmitted to the operator, taking into account the beam's shock vibration motions. The steady state motion of a dynamic beam pattern is studied, and results of experimental tests with existing equipment are presented.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 9-14
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  • 15
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    Stresses in dome-shaped shells of revolution with discontinuities at the apex (1974)
    In:  CASI
    Details
    Publikationsdatum: 2006-04-02
    Beschreibung: Asymptotic solutions of Novozhilov's equations of shells of revolution are derived for axisymmetric and first harmonic loadings. The solutions obtained are valid throughout the shallow and nonshallow regions. Stresses in dome shaped shells of revolution with a discontinuity in the form of a circular hole, a circular rigid insert, or a nozzle at the apex have been investigated. Numerical results are obtained for spheres, ellipsoids, and paraboloids, containing a discontinuity under a internal pressure and moment. Curves depicting stress distributions are given. The influence of three types of discontinuity on the stresses of the shells is also given.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: Multivariant Function Model Generation; 118 p
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  • 16
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    Current structural vibration problems associated with noise (1974)
    In:  CASI
    Details
    Publikationsdatum: 2011-10-14
    Beschreibung: As the performance of aerospace vehicles has increased, the noise generated by the propulsion system and by the passage of the vehicle through the air has also increased. Further increases in performance are now underway for space vehicles such as the space shuttle vehicle and for short distance takeoff and landing (STOL) aircraft, and are being planned for supersonic aircraft. The flight profiles and design features of these high-performance vehicles are reviewed and an estimate made of selected noise-induced structural vibration problems. Considerations for the prevention of acoustic fatigue, noise transmission, and electronic instrument malfunction are discussed.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: AGARD Noise Mech.; 16 p
    Format: text
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  • 17
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    Inclusion of transverse shear deformation in finite element displacement formulations (1974)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-16
    Beschreibung: A stiffness matrix is derived for a beam element with transverse shear deformation. It is shown that straightforward energy minimization yields the correct stiffness matrix in displacement formulations when transverse shear effects are considered. Since the TIM4 beam element does not represent the geometric boundary conditions for a cantilever beam the rotation of the normal must be retained as a grid point degree of freedom.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: AIAA Journal; 12; Nov. 197
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  • 18
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    Alterations in left ventricular volumes induced by Valsalva manoeuvre (1974)
    In:  Other Sources
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    Publikationsdatum: 2011-08-16
    Beschreibung: Five patients were studied with left ventriculography during different phases of the Valsalva manoeuvre. Small doses of contrast medium allowed adequate repetitive visualization of the left ventricle for volume calculation. During strain phase, the volume of the left ventricle decreased by nearly 50 per cent in each case, and stroke volume and cardiac output also dropped strikingly. Release of straining was attended by a sharp rebound of left ventricular volume to control levels, with a transient surge of increased cardiac output 42 per cent above that of the resting state.
    Schlagwort(e): BIOSCIENCES
    Materialart: British Heart Journal; 36; July 197
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  • 19
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    Microcraters formed in glass by projectiles of various densities (1974)
    In:  Other Sources
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    Publikationsdatum: 2011-08-16
    Beschreibung: An experiment was conducted investigating the effect of projectile density on the structure and size of craters in soda lime glass and fused quartz. The projectiles were spheres of polystyrene-divinylbenzene (PS-DVB), aluminum, and iron with velocities between 0.5 and 15 km/sec and diameters between 0.4 and 5 microns. The projectile densities spanned the range expected for primary and secondary particles of micrometer size at the lunar surface, and the velocities spanned the lower range of micrometeoroid velocities and the upper range of secondary projectile velocities. There are changes in crater morphology as the impact velocity increases, and the transitions occur at lower velocities for the projectiles of higher density. The sequence of morphological features of the craters found for PS-DVB impacting soda lime glass for increasing impact velocity, described in a previous work (Mandeville and Vedder, 1971), also occurs in fused quartz and in both targets with the more dense aluminum and iron projectiles. Each transition in morphology occurs at impact velocities generating a certain pressure in the target. High density projectiles require a lower velocity than low-density projectiles to generate a given shock pressure.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: Journal of Geophysical Research; 79; Aug. 10
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  • 20
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    Apollo space crew cardiovascular evaluations (1974)
    In:  Other Sources
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    Publikationsdatum: 2011-08-16
    Beschreibung: Cardiovascular responses associated with pre- and postflight orthostatic tolerance evaluations of Apollo crewmen are presented with a brief historical survey and a discussion of their implications for future manned space flight. Heart rates were increased while systolic and pulse pressures were decreased during the immediate postflight orthostatic evaluation. A postflight elevation in resting heart rate was a less frequent finding.
    Schlagwort(e): BIOSCIENCES
    Materialart: Aerospace Medicine; 45; Aug. 197
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  • 21
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    Recovery of medically important microorganisms from Apollo astronauts (1974)
    In:  Other Sources
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    Publikationsdatum: 2011-08-16
    Beschreibung: Microbiological samples were obtained from the crewmembers of the Apollo 13, 14, 15, 16, and 17 spaceflights. These specimens were analyzed for the presence of medically important microorganisms with Staphylococcus aureus, Pseudomonas aeruginosa, Tricophyton mentagrophytes, Tricophyton rubrum, and Candida albicans being discussed in detail. Preflight isolation of crewmembers was found to coincide with a complete absence of inflight disease events and is recommended for future spaceflights. No autoinfection response (microbial shock) occurred after any of the reported spaceflights.
    Schlagwort(e): BIOSCIENCES
    Materialart: Aerospace Medicine; 45; Aug. 197
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  • 22
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    Approximate techniques of structural reanalysis (1974)
    In:  Other Sources
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    Publikationsdatum: 2011-08-16
    Beschreibung: A study is made of two approximate techniques for structural reanalysis. These include Taylor series expansions for response variables in terms of design variables and the reduced-basis method. In addition, modifications to these techniques are proposed to overcome some of their major drawbacks. The modifications include a rational approach to the selection of the reduced-basis vectors and the use of Taylor series approximation in an iterative process. For the reduced basis a normalized set of vectors is chosen which consists of the original analyzed design and the first-order sensitivity analysis vectors. The use of the Taylor series approximation as a first (initial) estimate in an iterative process, can lead to significant improvements in accuracy, even with one iteration cycle. Therefore, the range of applicability of the reanalysis technique can be extended. Numerical examples are presented which demonstrate the gain in accuracy obtained by using the proposed modification techniques, for a wide range of variations in the design variables.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: Computers and Structures; 4; Aug. 197
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  • 23
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    Alteration of pituitary-adrenal dynamics induced by a water deprivation regimen (1974)
    In:  Other Sources
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    Publikationsdatum: 2011-08-16
    Beschreibung: Experiments are described which were designed to assess the degree of adaptation that occurs in rats chronically exposed to the stress of a water-deprivation regimen and to determine if that adaptation represents a normalization of the hypothalamic-pituitary-adrenal axis. There were no significant differences in mean corticosterone concentrations among control nondeprived rats 1, 4, and 8 weeks after the start of the experiment. The water-deprived rats, however, had significantly elevated plasma steroids 1 and 4 weeks after the onset of deprivation as compared to controls, but not after 8 weeks. Thus, there was a significant decrease in mean plasma corticosterone levels during water deprivation from 1 week to 8 weeks.
    Schlagwort(e): BIOSCIENCES
    Materialart: Physiology and Behavior; 12; 1974
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  • 24
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    Effects of simulated weightlessness on responses of untrained men to +Gz acceleration (1974)
    In:  Other Sources
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    Publikationsdatum: 2011-08-16
    Beschreibung: This study documents bedrest-induced metabolic and physiologic changes in six untrained men exposed, following a two-week period of simulated weightlessness, to possible +Gz acceleration profiles anticipated for Space Shuttle vehicle travel. All subjects demonstrated decreased +Gz tolerance following simulated weightlessness. While only one of six subjects could not tolerate the +Gz profile in the control phase of the study, three of the six could not complete the postbed-rest study. The use of an inflated standard Air Force cutaway G-suit improved +Gz tolerance in all subjects, but two of six subjects still failed to complete the profile. These findings are discussed in reference to the selection of untrained humans for Space Shuttle vehicle travel.
    Schlagwort(e): BIOSCIENCES
    Materialart: Journal of Applied Physiology; 36; June 197
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  • 25
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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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    Publikationsdatum: 2011-08-16
    Beschreibung: Recent innovations in digital computer technology have enabled engineers to analyze shell structures of complex configurations without unduly restrictive approximations. An attempt is made to compare the various programs now generally available from the point of view of the advantages of the relative technique utilized, as well as the programmed state of the art. Many of the comparisons are based on the sample problems solved by the STARS-2 system of programs. These examples indicate both the structural detail which can be analyzed by, and the analytical capabilities available in, the numerical shell-of-revolution programs. All advantages and differences are demonstrated by use of solutions for realistic shell problems in the areas of statics, stability, vibrations, and dynamic response of shells subjected to time-dependent loadings.
    Schlagwort(e): STRUCTURAL MECHANICS
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  • 26
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    Forced vibrations of multi-component compliant tanks and feedlines (1974)
    In:  Other Sources
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    Publikationsdatum: 2011-08-16
    Beschreibung: An analytical and experimental research program was performed to investigate the effects of flexible tanks and lines and the total system dynamic response of a simple physical system which had some of the essential features of a liquid-fueled launch vehicle. Several vessel-wall materials were used to obtain a range of elastic moduli. Water was used to simulate the fuel and an electromagnetic shaker provided external excitation such as might originate from a rocket-propulsion system. Experimental data were compared to values obtained from mathematical models for the many degree-of-freedom lumped-mass representation.
    Schlagwort(e): STRUCTURAL MECHANICS
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  • 27
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    Nonproportional loading limit for structures (1974)
    In:  Other Sources
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    Publikationsdatum: 2011-08-16
    Beschreibung: The design of most structures involves ensuring integrity for several independent loading conditions. Often, it is rational to design these, exploiting the ductility of the materials to reduce structural costs. Then, ensuring integrity evokes the need for nonmonotonic limit analyses. A groundwork is laid for implementing these analyses. An alternate limit load characterization to that of Greenberg is provided, a mathematical statement of the problem leading to both monotonic (proportional) and nonmonotonic limit loads values is formulated, a direct limit load analysis procedure for analysis within a finite-element framework is described, and limit loads for sets of simple structures are evaluated. A direct limit analysis process is described, and monotonic limit loads are characterized. The process furnishes 'exact' values of limit loads with increasing efficiency as the number of structural elements and force redundancy decreases. Tests show that the accuracy of predicting nonmonotonic limit loads is very sensitive to the number of degrees of freedom in the analysis compared with the total number in the model.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: Computers and Structures; 4; Mar. 197
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  • 28
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    Determination of left ventricular size and shape (1974)
    In:  Other Sources
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    Publikationsdatum: 2011-08-16
    Beschreibung: Significant advances have occurred over the past 15 years in the ability to measure ventricular dimensions. Angiocardiography still remains the most reliable method for overall determination of chamber size and shape and serves as a standard for calibration or comparison for newer methods. Improvements in the use of radiographic methods over the next few years are anticipated with more extensive use of multiplane studies associated with repeated injections of improved contrast materials that produce fewer physiological effects or with substances that adhere to the endocardial surfaces. It is also anticipated that existing methods for automatically obtaining dimensional information from X rays will be continued and improved.
    Schlagwort(e): BIOSCIENCES
    Materialart: Circulation Research; 34; Jan. 197
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  • 29
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    Serotonin and pituitary-adrenal function (1974)
    In:  Other Sources
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    Publikationsdatum: 2011-08-16
    Beschreibung: An investigation is conducted to evaluate the response of the pituitary-adrenal system to a stress stimulus in the rat. In the investigation brain serotonin synthesis was inhibited with p-chlorophenylalanine. In other tests the concentration of serotonin was enhanced with precursors such as tryptophan or 5-hydroxytryptophan. On the basis of the results obtained in the study it is speculated that in some disease states there is a defect in serotonergic neuronal processes which impairs pituitary-adrenal feedback mechanisms.
    Schlagwort(e): BIOSCIENCES
    Materialart: Nature; 248; Mar. 29
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  • 30
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    Adhesive fracture mechanics (1974)
    In:  Other Sources
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    Publikationsdatum: 2011-08-16
    Beschreibung: In studies of fracture mechanics the adhesive fracture energy is regarded as a fundamental property of the adhesive system. It is pointed out that the value of the adhesive fracture energy depends on surface preparation, curing conditions, and absorbed monolayers. A test method reported makes use of a disk whose peripheral part is bonded to a substrate material. Pressure is injected into the unbonded central part of the disk. At a certain critical pressure value adhesive failure can be observed. A numerical stress analysis involving arbitrary geometries is conducted.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: International Journal of Fracture; 10; Mar. 197
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  • 31
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    Life span and fine structural changes in oxygen-poisoned drosophila melanogaster (1974)
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    Publikationsdatum: 2011-08-16
    Schlagwort(e): BIOSCIENCES
    Materialart: Aerospace Medicine; 45; Mar. 197
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  • 32
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    New triangular plate-bending finite element with transverse shear flexibility (1974)
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    Publikationsdatum: 2011-08-16
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: AIAA Journal; 12; Dec. 197
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  • 33
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    Irregular bilayer structure in vesicles prepared from Halobacterium cutirubrum lipids (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: Fluorescent probes were used to study the structure of the cell envelope of Halobacterium cutirubrum, and, in particular, to explore the effect of the heterogeneity of the lipids in this organism on the structure of the bilayers. The fluorescence polarization of perylene was followed in vesicles of unfractionated lipids and polar lipids as a function of temperature in 3.4 M solutions of NaCl, NaNO3, and KSCN, and it was found that vesicles of unfractionated lipids were more perturbed by chaotropic agents than polar lipids. The dependence of the relaxation times of perylene on temperature was studied in cell envelopes and in vesicles prepared from polar lipids, unfractionated lipids, and mixtures of polar and neutral lipids.
    Schlagwort(e): BIOSCIENCES
    Materialart: Biochimica et Biophysica Acta; 356; 1974
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  • 34
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    Human radiation tolerance (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: The acute radiation syndrome in man is clinically bounded by death at high dose levels and by the prodromal syndrome of untoward physiological effects at minimal levels of clinically effective exposure. As in lower animals, man experiences principally three acute modes of death from radiation exposure (Bond et al., 1965). These are known collectively as the lethal radiation syndromes: central nervous system death, gastrointestinal death, and hematopoietic death. The effect of multiple exposure on lethality, the effect of multiple exposure on hematopoietic recovery, and quantitative aspects of cell and tissue repair are discussed.
    Schlagwort(e): BIOSCIENCES
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  • 35
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    Ultrastructural response of rat lung to 90 days' exposure to oxygen at 450 mm Hg (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: Young Sprague-Dawley rats were exposed to 100% oxygen at 450 mm Hg in constant environment capsules for 90 days. Lung tissue examined by electron microscopy revealed a number of changes, many similar to those observed after exposure to oxygen at 760 mm Hg for shorter periods of time. Alterations in vesicle size and number and in mitochondrial matrix and cristae appear in both the endothelial and epithelial cells. Blebbing and rarefication of cytoplasm occur in both cell layers of the alveolo-capillary wall. Also seen are fluid in the basement membrane, platelets in the capillaries, and alveolar fluid and debris. All of these alterations occur at 1 atm exposure. However, after exposure to 450 mm Hg the changes are not as widespread nor as destructive as they are at the higher pressure.
    Schlagwort(e): BIOSCIENCES
    Materialart: Aerospace Medicine; 45; Sept
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  • 36
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    Interactive design of large end rings on stiffened conical shells using composites (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: Design study methods and results for a composite reinforced base ring for the conical aeroshell structure of the planetary lander vehicle for Project Viking, an unmanned mission to Mars, are presented. The aeroshell is a ring and stringer-stiffened conical shell structure having a half angle of 70 degrees with a large base ring mounted at the outer edge of the cone and a large pay-load ring in the interior with many smaller rings spaced along the inside shell surface. The purpose of the structure is to develop the aerodynamic drag required to decelerate the lander in the Mars atmosphere to facilitiate a soft landing. The design of a shell structure of this complexity requires the use of the latest technology available in a large general-purpose shell buckling program. The large general-purpose non-linear shell buckling program (BOSOR 2) which was used for this purpose is described.
    Schlagwort(e): STRUCTURAL MECHANICS
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  • 37
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    Microbial detection method based on sensing molecular hydrogen (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: An approach involving the measurement of hydrogen evolution by test organisms was used to detect and enumerate various members of the Enterobacteriaceae group. The experimental setup for measuring hydrogen evolution consisted of a test tube containing two electrodes plus broth and organisms. The test tube was kept in a water bath at a temperature of 35 C. It is pointed out that the hydrogen-sensing method, coupled with the pressure transducer technique reported by Wilkins (1974) could be used in various experiments in which gas production by microorganisms is being measured.
    Schlagwort(e): BIOSCIENCES
    Materialart: Applied Microbiology; 27; May 1974
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  • 38
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    Treatment of the external epicondylitis of the humerus with a magnetic field (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: The therapeutic effect of a constant and varying magnetic field on epicondylitis of the humerus is studied on ninety patients. Good results are obtained from the treatment (recovery of 80%, considerable improvement in 14.5%). The method is recommended for clinical application.
    Schlagwort(e): BIOSCIENCES
    Materialart: Studies in Geomagnetism, Aeronomy and Solar Phys. (NASA-TT-F-15862); p 191-197
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  • 39
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    Effect of magnetic bracelets on the coagulation and anticoagulation systems of the blood of patients with hypertension (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: The data which have been obtained on the influence of magnetic bracelets on the coagulation and anticoagulation systems of the blood indicate that the wearing of magnetic bracelets results in a decrease in the coagulation activity of the blood and an increase in the activity of the anticoagulation system. These changes must be viewed as favorable for patients with cardiovascular pathology.
    Schlagwort(e): BIOSCIENCES
    Materialart: Studies in Geomagnetism, Aeronomy and Solar Phys. (NASA-TT-F-15862); p 167-190
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  • 40
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    Changes in the fibrinogen-fibrin system following a 20-hour exposure of rabbits to a magnetic field (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: Prolonged exposure of animals to a constant magnetic field resulted in a sharp increase in the amount of fibrinogen. The addition of EACA to the plasma of experimental rabbits as well as protamine sulfate caused an additional increase in the amount of fibrinogen. A 20-hour exposure was accompanied by phenomena of paralysis of the pelvic limbs and death of some of the animals.
    Schlagwort(e): BIOSCIENCES
    Materialart: Studies in Geomagnetism, Aeronomy and Solar Phys. (NASA-TT-F-15862); p 163-166
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  • 41
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    Influence of a constant magnetic field on the fibrinogen-fibrin system (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: The effect of a constant magnetic field with a strength of 2500 oersteds on the fibrinogen-fibrin system was studied in the organism of healthy rabbits with exposure times of 1 and 5 hours. The results obtained indicate disruptions in the stage of conversion of fibrinogen to fibrin and an increase in the amount of fibrinogen.
    Schlagwort(e): BIOSCIENCES
    Materialart: Studies in Geomagnetism, Aeronomy and Solar Phys. (NASA-TT-F-15862); p 157-161
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  • 42
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    Influence of a constant magnetic field on thrombocytes (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: In an experiment on white mice it was found that a constant electromagnetic field with strength of 250-275 oersteds is biologically active at an exposure of 55 minutes. Qualitative and morphological changes in thrombocytes 1-3 days following exposure reduced their numbers, prolonged blood coagulation time and increased the number of leucocytes.
    Schlagwort(e): BIOSCIENCES
    Materialart: Studies in Geomagnetism, Aeronomy and Solar Phys. (NASA-TT-F-15862); p 141-147
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  • 43
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    The protective effect of a constant magnetic field (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: The protective effect of a constant magnetic field sharply reduced spontaneous lysis of E. coli cells when subjected to ultraviolet radiation. A protective effect of a CMF was found in a study of tissue cultures of normally growing cells (kidney epithelium) and cancer cells (cells from a cancer of the larynx). The protective effect of a CMF is also seen in a combined exposure of tissue cultures to X-rays and CMF energy (strength of the CMF was 2000 oersteds with a gradient of 500 oersteds/cm). The data obtained are of interest to experimental oncology (development of new methods of treating malignant tumors).
    Schlagwort(e): BIOSCIENCES
    Materialart: Studies in Geomagnetism, Aeronomy and Solar Phys. (NASA-TT-F-15862); p 148-156
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  • 44
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    Method of magnetobiological indication in clinical laboratory practice (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: Data are presented on the use of the method of magnetobiological indication for defining the immunobiological state of patients with very serious diseases. It has been found that the enzymes of a patient react more sensitively to the energy from a magnetic field. It is important that the magnetoreactivity of the enzymes, like the cell forms of the blood in the patients, have a certain relationship to the clinical-nosological forms and the dynamics of the illness of the subject.
    Schlagwort(e): BIOSCIENCES
    Materialart: Studies in Geomagnetism, Aeronomy and Solar Phys. (NASA-TT-F-15862); p 129-140
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  • 45
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    Influence of a constant and variable magnetic field on the coagulation of human blood in vitro and in vivo (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: The influence of constant and varying magnetic fields on the coagulation of the blood was studied in experiments performed in vitro and vivo. In the in vitro tests it was found that a constant magnetic field with a strength of 100 or 200 oersteds influences the coagulation of the blood, retarding it in some cases and speeding up the coagulation time in others. In the in vivo studies, both retarding and accelerating effects were likewise observed with respect to the coagulation of the blood, but the nature of the change was a function of the background. A normalizing effect of the magnetic field on the coagulation of the blood was observed.
    Schlagwort(e): BIOSCIENCES
    Materialart: Studies in Geomagnetism, Aeronomy and Solar Phys. (NASA-TT-F-15862); p 124-128
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  • 46
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    Change in fibrinolytic activity under the influence of a constant magnetic field (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: The fibrinolytic activity of plasma changes under the influence of a constant magnetic field (CMF) with a strength of 250 or 2500 oersteds. CMF shows a tendency toward normalization of fibrinolytic processes in the presence of pathological disturbances in fibrinolysis activation.
    Schlagwort(e): BIOSCIENCES
    Materialart: Studies in Geomagnetism, Aeronomy and Solar Phys. (NASA-TT-F-15862); p 117-123
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  • 47
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    Change in blood coagulation indices as a function of the incubation period of plasma in a constant magnetic field (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: The influence of a constant magnetic field (CMF) with a strength of 250 and 2500 oersteds on the recalcification reaction and the tolerance of plasma to heparin was studied as a function of the exposure time of the plasma to the CMF. The maximum and reliable change in the activation of the coagulatory system of the blood was observed after a 20-hour incubation of the plasma in a CMF. As the exposure time increased, the recalcification reaction changed insigificantly; the difference between the mean arithmetic of the experiment and control values was not statistically reliable. The tolerance of the plasma to heparin as a function of the exposure time to the CMF of the plasma was considerably modified, an was statistically reliable.
    Schlagwort(e): BIOSCIENCES
    Materialart: Studies in Geomagnetism, aeronomy and Solar Phys. (NASA-TT-F-15862); p 109-116
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  • 48
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    Repeated action of a constant magnetic field on the blood coagulation system in artificially produced anemia (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: Changes are discussed in the coagulatory system of the blood in rabbits under the influence of a constant magnetic field of an intensity of 2500 oersteds against the background of artificially induced anemia. Reversibility of the changes produced and the presence of the adaptational effect are noted. Taking all this into consideration, the changes involving the coagulatory system of the blood which arise under the influence of a constant magnetic field may be considered to have a nerve-reflex nature.
    Schlagwort(e): BIOSCIENCES
    Materialart: Studies in Geomagnetism, Aeronomy and Solar Phys. (NASA-TT-F-15862); p 97-108
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  • 49
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    The influence of a constant magnetic field on the coagulatory system of the blood in an experiment (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: The influence of a constant magnetic field with a strength of 2500 oersteds on the coagulatory system of the blood in rabbits was studied; the animals were subjected to this field for one and five hours. The magnetic field acts on the coagulatory system of the blood after only one hour exposure. Repeated 5-hour exposures cause activation of the anticoagulatory system in the blood and causes distinctive effects on the subsequent changes in the coagulatory system of the blood. It is quite likely that in this instance the adaptational properties of the organism make themselves felt.
    Schlagwort(e): BIOSCIENCES
    Materialart: Studies in Geomagnetism, Aeronomy and Solar Phys. (NASA-TT-F-15862); p 82-96
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  • 50
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    Effect of a magnetic field of extremely low intensity on the coagulatory system of the blood (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: The influence of a magnetic field of 10,000 gamma on the conditions of the coagulatory system of rabbits was studied. The results from a number of experiments indicate that the action of a very weak magnetic field produces an increase in the coagulatory activity of the blood.
    Schlagwort(e): BIOSCIENCES
    Materialart: Studies in Geomagnetism, Aeronomy and Solar Phys. (NASA-TT-F-15862); p 73-81
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  • 51
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    Reactions of the nervous system to magnetic fields (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: This magnetobiological survey considers sensory, nervous, stress and genetic effects of magnetic fields on man and animals. It is shown that the nervous system plays an important role in the reactions of the organism to magnetic fields; the final biological effect is a function of the strength of the magnetic fields, the gradient, direction of the lines of force, duration and location of the action, and the functional status of the organism.
    Schlagwort(e): BIOSCIENCES
    Materialart: Studies in Geomagnetism, Aeronomy and Solar Phys. (NASA-TT-F-15862); p 59-72
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  • 52
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    Results of comparison of the dynamics of the epidemic process with changes in the planetary index of magnetic disturbance (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: Possible pathways for the action of factors related to solar activity and its magnetic effects on the epidemic process are discussed.
    Schlagwort(e): BIOSCIENCES
    Materialart: Studies in Geomagnetism, Aeronomy and Solar Phys. (NASA-TT-F-15862); p 31-38
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  • 53
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    Statistical evaluation of the significance of the influence of abrupt changes in solar activity on the dynamics of the epidemic process (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: Statistical evaluations of the significance of the relationship of abrupt changes in solar activity and discontinuities in the multi-year pattern of an epidemic process are reported. They reliably (with probability of more than 99.9%) show the real nature of this relationship and its great specific weight (about half) in the formation of discontinuities in the multi-year pattern of the processes in question.
    Schlagwort(e): BIOSCIENCES
    Materialart: Studies in Geomagnetism, Aeronomy and Solar Phys. (NASA-TT-F-15862); p 49-58
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  • 54
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    The problem of the periodicity of the epidemic process (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: An analysis of data from epidemics makes it possible to determine their principal causes, governed by environmental factors (solar activity, etc.) The results of an analysis of the periodicity of the epidemic process in the case of diphtheria are presented which was conducted with the aid of autocorrelation and spectral methods of analysis. Numerical data (annual figures) are used on the dynamics of diphtheria in 50 regions (points) with a total duration of 2,777 years.
    Schlagwort(e): BIOSCIENCES
    Materialart: Studies in Geomagnetism, Aeronomy and Solar Phys. (NASA-TT-F-15862); p 39-48
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  • 55
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    The influence of weather on fibrinolysis and fibrinogenolysis (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: Analysis of fibrinolysis and fibrinogenolysis indices by month showed an increase in the activity of these processes from winter to summer (1967-1968). At all seasons of the year, fibrinolysis and fibrinogenolysis increase during weather of the cyclonic type with passage of fronts and sharp fluctuations in meteorological factors in the atmosphere.
    Schlagwort(e): BIOSCIENCES
    Materialart: Studies in Geomagnetism, Aeronomy and Solar Phys. (NASA-TT-F-15862); p 24-30
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  • 56
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    Fibrinolysis and fibrinogenolysis on magnetically-active days (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: On magnetically-active days, activation of fibrinolysis and fibrinogenolysis is observed. The increase in fibrinolysis and fibrinogenolysis begins on the day of the onset of a magnetic storm, reaching a maximum in 24 hours. Activation is higher on days with magnetic storms with a sudden onset and a C index of 1.5-2.0.
    Schlagwort(e): BIOSCIENCES
    Materialart: Studies in Geomagnetism, Aeronomy and Solar Phys. (NASA-TT-F-15862); p 16-20
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  • 57
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    Influence of synoptic processes on fibrinolysis and fibrinogenolysis in healthy persons (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: It is shown that on days with frontal activity in the atmosphere the levels of fibrinolysis and fibrinogenolysis are increased. The reactions of fibrinolysis and fibrinogenolysis to the passage of warm and cold fronts varies with the season of the year.
    Schlagwort(e): BIOSCIENCES
    Materialart: Studies in Geomagnetism, Aeronomy and Solar Phys. (NASA-TT-F-15862); p 20-23
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  • 58
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    Influence of solar activity on fibrinolysis and fibrinogenolysis (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: During periods of high solar activity fibrinolysis and fibrinogenolysis are increased. A direct correlative relationship is established between the indices of fibrinolysis, fibrinogenolysis and solar flares which were recorded two days before the blood was collected for analysis.
    Schlagwort(e): BIOSCIENCES
    Materialart: Studies in Geomagnetism, Aeronomy and Solar Phys. (NASA-TT-F-15862); p 12-15
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  • 59
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    Notes on the concept of normal values employed in clinical practice (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: The question of the considerable variations in various blood parameters under the influence of changes in environmental factors is discussed. Recommendations are given that so-called normal values should be given special attention. Fibrinolytic and fibrinogenolytic activity studies on the blood in healthy human beings revealed significant differences for individual months and even on specific days. Changes in the activity of fibrinolysis and fibrinogenolysis show a correlation with changes in the meteorological conditions, seasonal variations and changes in solar activity.
    Schlagwort(e): BIOSCIENCES
    Materialart: Studies in Geomagnetism, Aeronomy and Solar Phys. (NASA-TT-F-15862); p 9-11
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  • 60
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    Heliobiology, its development, successes and tasks (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: Heliobiology studies the influence of changes in solar activity on life. Considered are the influence of periodic solar activity on the development and growth of epidemics, mortality from various diseases, the functional activity of the nervous system, the development of psychic disturbances, the details of the development of microorganisms and many other phenomena in the living world.
    Schlagwort(e): BIOSCIENCES
    Materialart: Studies in Geomagnetism, Aeronomy and Solar Phys. (NASA-TT-F-15862); p 1-8
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  • 61
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    Boundary value problems with incremental plasticity in granular media (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: 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.
    Schlagwort(e): STRUCTURAL MECHANICS
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  • 62
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    A solution to the contact of two rough spherical surfaces (1974)
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    Publikationsdatum: 2011-08-16
    Beschreibung: 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.
    Schlagwort(e): STRUCTURAL MECHANICS
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  • 63
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    Rhythmic variation in heart rate and respiration rate during space flight - Apollo 15 (1974)
    In:  Other Sources
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    Publikationsdatum: 2011-08-16
    Beschreibung: As part of the operational biomedical monitoring for Apollo manned missions, ECG and respiration rate are telemetered at selected intervals to mission control. The data were collected as part of this monitoring program. These data were evaluated for circadian and ultradian rhythmicity because of their uniqueness. The ability to detect and quantitate biorhythms in living systems during space flight is an important aspect of evaluating hypotheses concerning the underlying mechanisms of these phenomena. Circadian variation in heart rate during space flight is demonstrated here. In analyzing generated time series data it has been found that period discrimination is much better than the theoretical limit.
    Schlagwort(e): BIOSCIENCES
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  • 64
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    Hydrocortisone and ACTH levels in manned spaceflight (1974)
    In:  Other Sources
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    Publikationsdatum: 2011-08-16
    Beschreibung: The plasma hydrocortisone, plasma ACTH, and urinary hydrocortisone values were recorded for each man of the crews of Apollo flights eight through fifteen, 30, 14, and 5 days before flight, immediately after spaceflight recovery, and on future days until the return of most variables to preflight values. The plasma and urinary preflight hydrocortisone values were significantly higher than the postflight values. This result is discussed in terms of three possible explanations: (1) the adrenal-cortical function is suppressed during spaceflight; (2) the activity in flight may amount to stressful exercise, which tests have shown can cause a decrease in plasma adrenocortical hormones; and (3) the in-flight work-rest cycles may be such as to affect the circadian periodicity of the pituitary-adrenal function.
    Schlagwort(e): BIOSCIENCES
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  • 65
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    Fine structure of tannin accumulations in callus cultures of Pinus elliotti /slash pine/ (1974)
    In:  Other Sources
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    Publikationsdatum: 2011-08-16
    Schlagwort(e): BIOSCIENCES
    Materialart: Canadian Journal of Botany; 52; 3, 19; 1974
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  • 66
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    Mixed mode stress field effect in adhesive fracture (1974)
    In:  Other Sources
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    Publikationsdatum: 2011-08-16
    Beschreibung: 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.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: International Journal of Fracture; 10; Dec. 197
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  • 67
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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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    Publikationsdatum: 2011-08-16
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: AIAA Journal; 12; Oct. 197
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  • 68
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    Auditory and visual evoked potentials during hyperoxia (1974)
    In:  Other Sources
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    Publikationsdatum: 2011-08-16
    Beschreibung: Experimental study of the auditory and visual averaged evoked potentials (AEPs) recorded during hyperoxia, and investigation of the effect of hyperoxia on the so-called contingent negative variation (CNV). No effect of hyperoxia was found on the auditory AEP, the visual AEP, or the CNV. Comparisons with previous studies are discussed.
    Schlagwort(e): BIOSCIENCES
    Materialart: Electroencephalography and Clinical Neurophysiology; 37; Oct. 197
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  • 69
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    Phase relationships between circadian rhythms and the environment in humans during hypokinesis (1974)
    In:  Other Sources
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    Publikationsdatum: 2011-08-16
    Schlagwort(e): BIOSCIENCES
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  • 70
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    The action of ultrasounds on Bezostaia 1 winter wheat grown in sand pots treated with Knop solution (1974)
    In:  Other Sources
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    Publikationsdatum: 2011-08-16
    Beschreibung: The results of 3 years of research are presented concerning the increase in length and weight of the aerial biomass as compared with the underground biomass, as well as the productivity indexes of Bezostaia 1 winter wheat. The experiment involved two varieties, each of them with nine repetitions. Sterile sifted sand treated several times with a Knop solution during the vegetative period was used as a seed bed. The seeds were kept in water for 2 hours before treatment. Biometric and statistical measurements showed significant responses in the treated varieties.
    Schlagwort(e): BIOSCIENCES
    Materialart: the 4th Natl. Conf. on Acoustics, Vol. 2, B (NASA-TT-F-15663); p 244-249
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  • 71
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    New experimental contributions to understanding the effect of ultrasonic irradiation on tomatoes (1974)
    In:  Other Sources
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    Publikationsdatum: 2011-08-16
    Beschreibung: Irradiation of Aurora 100 tomatoes by a hydrodynamic ultrasonic generator with a frequency of 25 kHz per sec intensifies seed germination and the growth of the plants, causing precosity and increasing the output by 15.63 to 37.65%. The most effective radiation time (between 20 and 40 min) intensifies the phenophases. It causes some increase in output and changes in the chemical compositions of the fruits.
    Schlagwort(e): BIOSCIENCES
    Materialart: The 4th Natl. Conf. on Acoustics, Vol. 2, B (NASA-TT-F-15663); p 238-242
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  • 72
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    Echocardiography of the aortic valve. I - Studies of normal aortic valve, aortic stenosis, aortic regurgitation, and mixed aortic valve disease (1974)
    In:  Other Sources
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    Publikationsdatum: 2011-08-16
    Schlagwort(e): BIOSCIENCES
    Materialart: British Heart Journal; 36; Apr. 197
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  • 73
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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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    Publikationsdatum: 2011-08-16
    Beschreibung: 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.
    Schlagwort(e): STRUCTURAL MECHANICS
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  • 74
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    Effect of bioisolation and the intestinal flora of mice upon evaluation of an Apollo diet (1974)
    In:  Other Sources
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    Publikationsdatum: 2011-08-16
    Schlagwort(e): BIOSCIENCES
    Materialart: Aerospace Medicine; 45; May 1974
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  • 75
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    Angiotensinase activity of dipeptidyl aminopeptidase I /cathepsin C/ of rat liver (1974)
    In:  Other Sources
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    Publikationsdatum: 2011-08-16
    Schlagwort(e): BIOSCIENCES
    Materialart: Journal of Biological Chemistry; 249; Jan. 10
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  • 76
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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
    Publikationsdatum: 2012-05-22
    Beschreibung: 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.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: AGARD Low Cycle High Temp. Fatigue; 47 p
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  • 77
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    Identification of structural parameters from helicopter dynamic test data (1974)
    In:  CASI
    Details
    Publikationsdatum: 2016-06-07
    Beschreibung: 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.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: NASA. Ames Res. Center Rotorcraft Dyn.; p 239-248
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  • 78
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    Application of antiresonance theory to helicopters (1974)
    In:  CASI
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    Publikationsdatum: 2016-06-07
    Beschreibung: 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.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: NASA. Ames Res. Center Rotorcraft Dyn.; p 101-106
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  • 79
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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
    Publikationsdatum: 2016-06-07
    Beschreibung: 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.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: NASA. Ames Res. Center Rotorcraft Dyn.; p 67-80
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  • 80
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    Role of gravity in preparative electrophoresis (1974)
    In:  Other Sources
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    Publikationsdatum: 2019-01-25
    Beschreibung: Electrophoresis has contributed significantly to the methodology of biological sciences, and shows the potential for large scale fractionation of a wide range of medically important substances, including living cells. Gravity plays an important role in the electrophoretic process, and hence the importance of the NASA effort to develop a zero-gravity separation facility as part of its shuttle program. The current state of art in electrophoresis is reviewed with particular emphasis on the role of gravity and the possible use of istachophoresis. This technique utilizes a discontinuous buffer system, and appears to be the only high resolution electrophoretic technique currently available for separation of living cells.
    Schlagwort(e): BIOSCIENCES
    Materialart: Proc. of the 3d Space Processing Symp. on Skylab Results, Vol. 2; p 729-253
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  • 81
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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
    Publikationsdatum: 2019-06-27
    Beschreibung: 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.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: NASA-TN-D-7346 , A-4966
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  • 82
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    Transverse vibrations of non-uniform beams (1974)
    In:  Other Sources
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    Publikationsdatum: 2019-06-27
    Beschreibung: 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.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: Journal of Sound and Vibration; 37; Dec. 22
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  • 83
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    Non-linear behavior of fiber composite laminates (1974)
    In:  CASI
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    Publikationsdatum: 2019-06-27
    Beschreibung: 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.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: NASA-CR-2313 , TFR/7309
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  • 84
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    Failure criteria for viscoelastic materials (1974)
    In:  CASI
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    Publikationsdatum: 2019-06-27
    Beschreibung: 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.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: NASA-CR-138125 , GALCIT-120
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  • 85
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    Advance development of a technique for characterizing the thermomechanical properties of thermally stable polymers (1974)
    In:  CASI
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    Publikationsdatum: 2019-06-27
    Beschreibung: 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.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: NASA-CR-138123
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  • 86
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    Quantitative values of blood flow through the human forearm, hand, and finger as functions of temperature (1974)
    In:  CASI
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    Publikationsdatum: 2019-06-27
    Beschreibung: A literature search was made to obtain values of human forearm, hand and finger blood flow as functions of environmental temperature. The sources used include both government and laboratory reports and the research presented in the open literature. An attempt was made to review many of the more quantitative noninvasive determinations and to collate the results in such a way as to yield blood flow values for each body segment as continuous functions of temperature. A brief review of the various ways used to measure blood flow is included along with an abstract of each work from which data was taken.
    Schlagwort(e): BIOSCIENCES
    Materialart: NASA-TM-X-62342
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  • 87
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    Circadian, endocrine, and metabolic effects of prolonged bedrest: Two 56-day bedrest studies (1974)
    In:  CASI
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    Publikationsdatum: 2019-06-27
    Beschreibung: Two bedrest studies of 56 days each have been conducted to evaluate the effects of prolonged bedrest on circadian synchrony and endocrine and metabolic function. Measurements included the pituitary-adrenal, thyroid, parathyroid, insulin-glucose-growth hormones, catecholamine excretion, body temperature, and heart rate. The results indicated that a rigorous regimen of exercise did not prevent the endocrine and metabolic effects of prolonged bedrest. Changes in circadian, endocrine, and metabolic functions in bedrest appear to be due to changes in hydrostatic pressure and lack of postural cues rather than to inactivity, confinement, or the bleeding schedule. Prolonged bedrest, particularly beyond 24 days, resulted in rhythm desynchronization in spite of well regulated light/dark cycles, temperature, humidity, activity, and meal times and meal composition and in increased lability of all endocrine parameter measured. It also resulted in an apparent insensitivity of the glucose response to insulin, of cortisol secretion to ACTH, and of growth hormone secretion to hypoglycemia.
    Schlagwort(e): BIOSCIENCES
    Materialart: NASA-TM-X-3051 , A-5339
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  • 88
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    Analysis of laminated, composite, circular cylindrical shells with general boundary conditions (1974)
    In:  CASI
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    Publikationsdatum: 2019-06-27
    Beschreibung: 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.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: NASA-TR-R-412 , L-8828
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  • 89
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    Enzyme activity in terrestrial soil in relation to exploration of the Martian surface (1974)
    In:  CASI
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    Publikationsdatum: 2019-06-27
    Beschreibung: Sensitive tests for the detection of extracellular enzyme activity in Martian soil was investigated using simulated Martian soil. Enzyme action at solid-liquid water interfaces and at low humidity were studied, and a kinetic scheme was devised and tested based on the growth of microorganisms and the oxidation of ammonium nitrite.
    Schlagwort(e): BIOSCIENCES
    Materialart: NASA-CR-138587
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  • 90
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    Holographic nondestructive tests performed on composite samples of ceramic-epoxy-fiberglass sandwich structure (1974)
    In:  CASI
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    Publikationsdatum: 2019-06-27
    Beschreibung: 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.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: NASA-TR-R-430 , M-461
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  • 91
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    Procedures for experimental measurement and theoretical analysis of large plastic deformations (1974)
    In:  CASI
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    Publikationsdatum: 2019-06-27
    Beschreibung: 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.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: NASA-TM-X-3027 , E-7661
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  • 92
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    Analysis of three-point-bend test for materials with unequal tension and compression properties (1974)
    In:  CASI
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    Publikationsdatum: 2019-06-27
    Beschreibung: 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.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: NASA-TN-D-7572 , E-7544
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  • 93
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    FORTRAN 4 programs for summarization and analysis of fracture trace and lineament patterns (1974)
    In:  CASI
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    Publikationsdatum: 2019-06-27
    Beschreibung: 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.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: NASA-TM-X-70596 , X-644-74-3
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  • 94
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    Sensitivity analysis of torsional vibration characteristics of helicopter rotor blades. Part 2: Aerodynamics and sensitivity analysis (1974)
    In:  CASI
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: 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.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: NASA-CR-2380
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
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  • 95
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    Bone mineral measurement from Apollo experiment M-078 (1974)
    In:  CASI
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: Loss of mineral from bone during periods of immobilization, recumbency, or weightlessness is examined. This report describes the instrumentation, technique, and bone mineral changes observed preflight and postflight for the Apollo 14, 15, and 16 missions. The bone mineral changes documented during the Apollo Program are reviewed, and their relevance to future missions is discussed.
    Schlagwort(e): BIOSCIENCES
    Materialart: NASA-TM-X-58110 , JSC-08680
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
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  • 96
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    Assembly and analysis of fragmentation data for liquid propellant vessels (1974)
    In:  CASI
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: 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.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: NASA-CR-134538
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
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  • 97
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    Stress anisotropy and concentration effects in high pressure measurements (1974)
    In:  CASI
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: 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.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: NASA-CR-142600 , REPT-2345
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
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  • 98
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    Elastic moduli of precompressed pyrophyllite used in ultrahigh pressure research (1974)
    In:  CASI
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: 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%.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: NASA-CR-142598 , REPT-2366
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
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  • 99
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    Contact and crack problems for an elastic wedge (1974)
    In:  CASI
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: 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.
    Schlagwort(e): STRUCTURAL MECHANICS
    Materialart: NASA-CR-132640
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
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  • 100
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    Test results on the Viking gas chromatograph-mass spectrometer experiment (1974)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: The gas chromatograph-mass spectrometer instrument to be utilized in the Viking 1975 Molecular Analysis experiment has undergone preliminary testing in its flight configured version. A synthetic mixture of 24 components as well as a sample of the Murchison meteorite has been used for this purpose. The resulting data not only allowed the identification of most of the organic compounds known to be present, but also revealed the identity of a few unexpected ones. Thus, the sensitivity and reliability of the instrument and data system are satisfactorily demonstrated.
    Schlagwort(e): BIOSCIENCES
    Materialart: Origin of Life; 5; July-Oct
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
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