The direct calculation of the H-function for completely noncoherent scattering
H-function integrals for noncoherent isotropic scattering for two level atom, tabulating numerical values for Lorentz scattering profile
Warming, R. F.↗
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On ignoring the singularity in numerical quadrature
Convergence theorem for singular integrands numerical quadratures, assuming domination near singularity by monotone integrable function
Miller, R. K.↗
Transition probabilities for Ar I
Transition probabilities for Ar I, using Coulomb approximation values of radial wave function integral
Chen, C. J.↗
A rotary actuator for space missions
A new rotary actuator is reported that consists of a motor functionally integrated with the transmission of a ring gear in a single element which is driven by the rotating magnetic vector in the stator. Because the number of teeth on the ring gear is different from that on the fixed ground gear, the ring gear rotates at a fraction of a revolution and simultaneously rotates the output gear in one eccentric cycle in the opposite direction. The advantages of the design are that only two bearings are required on a low speed output shaft.
Devine, E. J.↗
Effects of the space flight environment on man's immune system. II - Lymphocyte counts and reactivity.
The present studies were undertaken to assess the effects of the environment of space flights on the cellular division of the human immune system. Peripheral blood absolute lymphocyte counts were determined at various preflight and postflight intervals for the 21 crewmen of Apollo Missions 7-13. Mean lymphocyte numbers tended to exhibit a delayed significant but fluctuating increase shortly after recovery, although a variety of responses was seen in individual astronauts. The in vitro reactivity of lymphocytes, reflected by RNA and DNA synthesis rates by unstimulated and PHA-stimulated lymphocytes tissue-cultured preflight and postflight from the same participants, was found to remain within previously established normal ranges. These results indicate that functional integrity of cellular immune potential as reflected by in vitro techniques is maintained during this spaceflight experience.
Fischer, G. L.↗
Seismic analysis of nuclear power plant structures
Primary structures for nuclear power plants are designed to resist expected earthquakes of the site. Two intensities are referred to as Operating Basis Earthquake and Design Basis Earthquake. These structures are required to accommodate these seismic loadings without loss of their functional integrity. Thus, no plastic yield is allowed. The application of NASTRAN in analyzing some of these seismic induced structural dynamic problems is described. NASTRAN, with some modifications, can be used to analyze most structures that are subjected to seismic loads. A brief review of the formulation of seismic-induced structural dynamics is also presented. Two typical structural problems were selected to illustrate the application of the various methods of seismic structural analysis by the NASTRAN system.
Go, J. C.↗
Determination of the availability of appropriate aged flight rocket motors
A program to identify surplus solid rocket propellant engines which would be available for a program of functional integrity testing was conducted. The engines are classified as: (1) upper stage and apogee engines, (2) sounding rocket and launch vehicle engines, and (3) jato, sled, and tactical engines. Nearly all the engines were available because their age exceeds the warranted shelf life. The preference for testing included tests at nominal flight conditions, at design limits, and to establish margin limits. The principal failure modes of interest were case bond separation and grain bore cracking. Data concerning the identification and characteristics of each engine are tabulated. Methods for conducting the tests are described.
Martin, P. J.↗
Statistical parameters of reverberating fields, calculated by computer
A method, developed for making measurements in reverberation chambers in the steady state mode, is reported. Spatial distribution patterns of the square of the sound pressure vs type of exciting signal were produced theoretically and checked experimentally in a reverberation chamber. Results of measurements of spatial irregularities of the field with pure tones and with noise bands in the 200 to 2,000 Hz frequency range were used for calculating statistical parameters of the reverbation fields by computer. The calculation program included determination of density probability function, integral distribution pattern, mathematical expectation, normalized dispersion of the mean square of the pressure.
Lebedeva, I. V.↗
The generation of gravitational waves. 1. Weak-field sources: A plug-in-and-grind formalism
A plug-in-and-grind formalism is derived for calculating the gravitational waves emitted by any system with weak internal gravitational fields. If the internal fields have negligible influence on the system's motions, then the formalism reduces to standard linearized theory. Whether or not gravity affects the motions, if the motions are slow and internal stresses are weak, then the new formalism reduces to the standard quadrupole-moment formalism. In the general case the new formalism expresses the radiation in terms of a retarded Green's function for slightly curved spacetime, and then breaks the Green's-function integral into five easily understood pieces: direct radiation, produced directly by the motions of the sources; whump radiation, produced by the the gravitational stresses of the source; transition radiation, produced by a time-changing time delay (Shapiro effect) in the propagation of the nonradiative, 1/r field of the source; focussing radiation produced when one portion of the source focusses, in a time-dependent way, the nonradiative field of another portion of the source, and tail radiation, produced by backscatter of the nonradiative field in regions of focussing.
Thorne, K. S.↗
The Concept Verification Testing of a materials science payload
The Concept Verification Testing (CVT) project at the Marshall Space Flight Center, Alabama is a developmental activity that supports Shuttle Payload projects such as Spacelab. It provides an operational one-g environment for testing NASA and other agency experiment and support systems concepts that may be used in Shuttle. A dedicated Materials Science Payload was tested in the General Purpose Laboratory (GPL) in December 1974 in order to assess the requirements of a Space Processing payload on a Spacelab type facility. Physical and functional integration of the experiments into the facility was studied, and the impact of the experiments on the facility (and vice versa) was evaluated. The Principal Investigators (PI) who had proposed experiments were onboard and in a consulting status on the ground. The significant results of the week-long simulation will be discussed.
Griner, C. S.↗
The generation of gravitational waves. I - Weak-field sources
This paper derives and summarizes a 'plug-in-and-grind' formalism for calculating the gravitational waves emitted by any system with weak internal gravitational fields. If the internal fields have negligible influence on the system's motions, the formalism reduces to standard 'linearized theory'. Independent of the effects of gravity on the motions, the formalism reduces to the standard 'quadrupole-moment formalism' if the motions are slow and internal stresses are weak. In the general case, the formalism expresses the radiation in terms of a retarded Green's function for slightly curved spacetime and breaks the Green's function integral into five easily understood pieces: direct radiation, produced directly by the motions of the source; whump radiation, produced by the 'gravitational stresses' of the source; transition radiation, produced by a time-changing time delay ('Shapiro effect') in the propagation of the nonradiative 1/r field of the source; focusing radiation, produced when one portion of the source focuses, in a time-dependent way, the nonradiative field of another portion of the source; and tail radiation, produced by 'back-scatter' of the nonradiative field in regions of focusing.
Thorne, K. S.↗
Hibernation, stress, intestinal functions, and catecholoamine turnover rate in hamsters and gerbils
Bioenergetic studies on hamsters during depressed metabolic states are reported. External support of blood glucose extended the survival times of hibernating animals. Radioresistance increased in hibernating as well as in hypothermic hamsters. Marked changes in hamster catecholamine turnover rates were observed during acclimatization to high temperature stress. High radioresistance levels of the gerbil gastrointestinal system were attributed in part to the ability of the gut to maintain functional integrity.
Musacchia, X. J.↗
Astronaut activity
Human factors pertinent to the design and operation of spacecraft are considered. The geometric characteristics of spacecraft that define the degree and type of confinement imposed on the crew and the character of equipment management and housekeeping necessary for hygiene, comfort and safety are discussed. The controls and displays of various spacecraft are described to indicate the degree to which crew functions become integral to functions of the total spacecraft. The contributions of the crew to system reliability and performance are summarized and the increasing significance of the crew's role in scientific observation and experimentation is noted.
Loftus, J. P., Jr.↗
The concept verification testing of materials science payloads
The concept Verification Testing (CVT) project at the Marshall Space Flight Center, Alabama, is a developmental activity that supports Shuttle Payload Projects such as Spacelab. It provides an operational 1-g environment for testing NASA and other agency experiment and support systems concepts that may be used in shuttle. A dedicated Materials Science Payload was tested in the General Purpose Laboratory to assess the requirements of a space processing payload on a Spacelab type facility. Physical and functional integration of the experiments into the facility was studied, and the impact of the experiments on the facility (and vice versa) was evaluated. A follow-up test designated CVT Test IVA was also held. The purpose of this test was to repeat Test IV experiments with a crew composed of selected and trained scientists. These personnel were not required to have prior knowledge of the materials science disciplines, but were required to have a basic knowledge of science and the scientific method.
Griner, C. S.↗
Hematology and immunology studies - The second manned Skylab mission
The hematologic and immunologic functions of the Skylab 3 astronauts were monitored during the preflight, inflight, and postflight phases of the mission. Plasma protein profiles showed high consistency in all phases. A transient suppression of lymphocyte responsiveness was observed postflight. A reduction in the circulating blood volume due to drops in both the plasma volume and red cell mass was found. The loss of red cell mass is most likely a suppressed erythrypoiesis. The functional integrity of the circulating red cells did not appear to be compromised in the course of flight.
Kimzey, S. L.↗
A spectral reflectance estimation technique using multispectral data from the Viking lander camera
A technique is formulated for constructing spectral reflectance curve estimates from multispectral data obtained with the Viking lander camera. The multispectral data are limited to six spectral channels in the wavelength range from 0.4 to 1.1 micrometers and most of these channels exhibit appreciable out-of-band response. The output of each channel is expressed as a linear (integral) function of the (known) solar irradiance, atmospheric transmittance, and camera spectral responsivity and the (unknown) spectral responsivity and the (unknown) spectral reflectance. This produces six equations which are used to determine the coefficients in a representation of the spectral reflectance as a linear combination of known basis functions. Natural cubic spline reflectance estimates are produced for a variety of materials that can be reasonably expected to occur on Mars. In each case the dominant reflectance features are accurately reproduced, but small period features are lost due to the limited number of channels. This technique may be a valuable aid in selecting the number of spectral channels and their responsivity shapes when designing a multispectral imaging system.
Park, S. K.↗
Data reformatting with less hardware
Dual-function integrated circuits use one shift register array instead of two to feed video data to seven tape channels thereby making system more reliable and less expensive than predecessor. Basic principle of reformatter is also applicable to multiplexing and frequency conversion circuits.
Engel, A.↗
Stresses from arbitrary loads on a circular crack
An inclusive theory is developed for stresses and displacements due to arbitrarily distributed normal and tangential loads acting on a circular crack in an infinite body. The representation chosen for the boundary conditions leads to solutions expressed as series of Bessel-function integrals of a class quite susceptible to further analysis and to rapid evaluation on modern computers. The load coefficients which appear in all the solution series bear intelligible interpretation, and stress intensity factors are related to them by simple formulas. The inclusiveness and tractability of the solutions qualify this theory to be a useful part of analyses for cracks in finite bodies in which the effective crack loads can assume many patterns.
Bell, J. C.↗