Proposed Changes in the Mission Control Jacchia Atmospheric Model

The space shuttle orbit prediction program uses the Jacchia Atmospheric model. The errors in the shuttle orbit prediction are investigated by not considering variations in solar flux or geomagnetic activity

Stability of real parametric polynomial discrete dynamical systems

We extend and improve the existing characterization of the dynamics of general quadratic real polynomial maps with coefficients that depend on a single parameter $\lambda$, and generalize this characterization to cubic real polynomial maps, in a consistent theory that is further generalized to real $m$-th degree real polynomial maps. In essence, we give conditions for the stability of the fixed points of any real polynomial map with real fixed points. In order to do this, we have introduced the concept of Canonical Polynomial Maps which are topologically conjugate to any polynomial map of the same degree with real fixed points. The stability of the fixed points of canonical polynomial maps has been found to depend solely on a special function termed Product Position Function for a given fixed point. The values of this product position determine the stability of the fixed point in question, when it bifurcates, and even when chaos arises, as it passes through what we have termed stability bands. The exact boundary values of these stability bands are yet to be calculated for regions of type greater than one for polynomials of degree higher than three.Comment: 23 pages, 4 figures, now published in Discrete Dynamics in Nature and Societ

A variational approach to necklaces formation in polyelectrolytes

By means of a variational approach we study the conditions under which a polyelectrolyte in a bad solvent will undergo a transition from a rod-like structure to a ``necklace'' structure in which the chain collapses into a series of globules joined by stretched chain segments.Comment: 6 pages, 4 figures (unfortunately big). Requires revtex, eps

Inorganic nanowires

Provided in one embodiment is a method of forming an inorganic nanowire, comprising: providing an elongated organic scaffold; providing a plurality of inorganic nanoparticles attached to the organic scaffold along a length of the organic scaffold; and fusing the nanoparticles attached to the organic scaffold to form an inorganic nanowire.Board of Regents, University of Texas Syste