8,328 research outputs found
Asteroid observations and planetary atmospheres analysis
Photoelectric observations of Eros and 30 other asteroids providing information on their surface characteristics, shape, and rotation axes are reported. Photographs of 18 asteroids and 4 comets yielding accurate position information on various dates were obtained. Photometric observations were made of the Saturn satellite lapetus, and electronographic images of the Uranus and Neptune satellites were obtained experimentally with a Spectracon tube to assess photometry by that method. Planetary patrol photographs of Venus and deconvolved area scans of Uranus were taken. UBV photometry of the Galilean satellites for the period 1973-1974 was completely analyzed and accepted for publication. An improved magnitude and color index for Minas were derived from 1974 area scans. A special photomultiplier tube with a suppressor grid was incorporated into a pulse-counting photometer with special added circuitry for carrying out the observations concerning the constancy of solar system dimensions over cosmic time
Studies in planetology, including the collection and interpretation of planetary information
The value of synoptic imaging of the planets is reported. The advantage of the Large Space Telescope, as compared with ground-based telescopes and planetary orbiters and flybys, is discussed. Desirable LST camera parameters and observing strategies are considered from the standpoint of synoptic imaging
Planetary Research Center
Extensive Earth-based photography of Mars, Jupiter, and Venus is presented which monitors the atmospheric and/or surface changes that take place day to day. Color pictures are included of the 1973 dust storm on Mars, showing the daily cycle of the storm's regeneration. Martian topography, and the progress of the storm is examined. Areas most affected by the storm are summarized
A Method of Hidden Markov Model Optimization for Use with Geophysical Data Sets
Abstract. Geophysics research has been faced with a growing need for automated techniques with which to process large quantities of data. A successful tool must meet a number of requirements: it should be consistent, require minimal parameter tuning, and produce scienti¯cally meaningful results in reasonable time. We introduce a hidden Markov model (HMM)-based method for analysis of geophysical data sets that attempts to address these issues. Our method improves on standard HMM methods and is based on the systematic analysis of structural local maxima of the HMM objective function. Preliminary results of the method as applied to geodetic and seismic records are presented.
How Your Neighbors Use Fertilizer
Fertilizer use in Iowa has increased considerably since 1938. Who uses it? When, where, why and how much? Here are the results of a study by Iowa State College and TVA to find more information on users and nonusers
Ytterbium-doped tantalum pentoxide waveguide lasers
We have demonstrated a Yb:Ta2O5 waveguide laser fabricated by RF magnetron sputtering on oxidised silicon. The waveguide laser was end-pumped with a laser diode at 977 nm and lasing was observed between 1015 and 1020 nm. The launched pump power threshold and slope efficiency were measured to be ~25 mW and 1.78 %, respectively
Untangling the Conceptual Isssues Raised in Reydon and Scholz’s Critique of Organizational Ecology and Darwinian Populations
Reydon and Scholz raise doubts about the Darwinian status of organizational ecology by arguing that Darwinian principles are not applicable to organizational populations. Although their critique of organizational ecology’s typological essentialism is correct, they go on to reject the Darwinian status of organizational populations. This paper claims that the distinction between replicators and interactors, raised in modern philosophy of biology but not discussed by Reydon and Scholz, points the way forward for organizational ecologists. It is possible to conceptualise evolving Darwinian populations providing the inheritance mechanism is appropriately specified. By this approach, adaptation and selection are no longer dichotomised, and the evolutionary significance of knowledge transmission is highlightedPeer reviewe
An appraisal of factors affecting the acceptance and use of fertilizer in Iowa, 1953
In 1953 Iowa State College and the Tennessee Valley Authority undertook a research project to determine (1) characteristics of Iowa farmers who use varying amounts of fertilizer and different fertilization practices, (2) informational sources important in the acceptance and use of fertilizer, (3) extent of use and handling of fertilizer on the farm and (4) quantitative relationships between fertilizer use and specified factors considered to influence fertilizer use. A scientifically selected statewide sample of 532 farms was the basis of this report.https://lib.dr.iastate.edu/specialreports/1013/thumbnail.jp
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