4,449 research outputs found
COMMUNITY AND RURAL DEVELOPMENT--IMPLICATIONS FOR ECONOMIC EXTENSION PROGRAMS
Community/Rural/Urban Development,
Explicit Global Coordinates for Schwarzschild and Reissner-Nordstroem
We construct coordinate systems that cover all of the Reissner-Nordstroem
solution with m>|q| and m=|q|, respectively. This is possible by means of
elementary analytical functions. The limit of vanishing charge q provides an
alternative to Kruskal which, to our mind, is more explicit and simpler. The
main tool for finding these global charts is the description of highly
symmetrical metrics by two-dimensional actions. Careful gauge fixing yields
global representatives of the two-dimensional theory that can be rewritten
easily as the corresponding four-dimensional line elements.Comment: 12 pages, 3 Postscript figures, sign error in Eq. (37) and below
corrected, references and Note added; to appear in Class. Quantum Gra
Water ice in the Kuiper belt
We examine a large collection of low-resolution near-infrared spectra of Kuiper Belt objects (KBOs) and centaurs in an attempt to understand the presence of water ice in the Kuiper Belt. We find that water ice on the surface of these objects occurs in three separate manners: (1) Haumea family members uniquely show surfaces of nearly pure water ice, presumably a consequence of the fragmentation of the icy mantle of a larger differentiated proto-Haumea; (2) large objects with absolute magnitudes of H < 3 (and a limited number to H = 4.5) have surface coverings of water ice—perhaps mixed with ammonia—that appears to be related to possibly ancient cryovolcanism on these large objects; and (3) smaller KBOs and centaurs which are neither Haumea family members nor cold-classical KBOs appear to divide into two families (which we refer to as "neutral" and "red"), each of which is a mixture of a common nearly neutral component and either a slightly red or very red component that also includes water ice. A model suggesting that the difference between neutral and red objects due to formation in an early compact solar system either inside or outside, respectively, of the ~20 AU methanol evaporation line is supported by the observation that methanol is only detected on the reddest objects, which are those which would be expected to have the most of the methanol containing mixture
Fertilizer Helps Control Erosion
Though it\u27s usually a good idea to adopt most erosion-control practices simultaneously, fertilizers can provide the man with insufficient capital with an effective stepping stone to get started on erosion control
Plow List or Disk?
Here\u27s a comparison of plowing, listing, subsurface tilling and disking for preparing seedbeds for corn in western Iowa. Other results will come later
Corn as a Nurse Crop
Corn as a nurse crop for establishing hay and pasture continues to look promising. Wide-spaced corn rows are making this possible. Results of tests in 1953 were encouraging-in spite of the long summer drouth
Forage Crops in Corn?
By widening corn rows and taking certain precautions, it\u27s possible to establish interplantings without a great loss in corn yields. Some problems remain to be overcome, but the future of this practice looks bright
- …